GB2279889A - Rotary drum filter - Google Patents
Rotary drum filter Download PDFInfo
- Publication number
- GB2279889A GB2279889A GB9414498A GB9414498A GB2279889A GB 2279889 A GB2279889 A GB 2279889A GB 9414498 A GB9414498 A GB 9414498A GB 9414498 A GB9414498 A GB 9414498A GB 2279889 A GB2279889 A GB 2279889A
- Authority
- GB
- United Kingdom
- Prior art keywords
- hollow member
- channel
- liquid
- leat
- impeller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/06—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums
- B01D33/11—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums arranged for outward flow filtration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/70—Filters with filtering elements which move during the filtering operation having feed or discharge devices
- B01D33/72—Filters with filtering elements which move during the filtering operation having feed or discharge devices for feeding
- B01D33/722—Filters with filtering elements which move during the filtering operation having feed or discharge devices for feeding containing fixed liquid displacement elements or cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/80—Accessories
- B01D33/801—Driving means, shaft packing systems or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/28—Position of the filtering element
- B01D2201/282—Filtering elements with a horizontal rotation or symmetry axis
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Filtration Of Liquid (AREA)
Abstract
River water drawn into a fish farm or industrial plant flows along a channel and is filtered by inward flow through the wall 20 of a partly submerged filter drum, which is closed at one end and whose other end includes an imperforate collar 22 enclosing a set of blades 24. The inside of the drum carries helical blades 26, and the drum is rotated by the action of the water on blades 24, 26, though there may also be a drive motor. The drum may be mounted in a frame for fitting into the channel (Fig. 4). The frame incorporates an end wall with an outlet aperture having a brush seal to engage the drum and a weir on the downstream side of the drum with an upper edge sloping across the channel. Wall 20 may be mesh or perforate material or a helically wound wedge-wire, or flattened expanded metal. <IMAGE>
Description
Filtration Apparatus
This invention relates to a filtration apparatus and more particularly, but not exclusively, to filtration apparatus for filtering liquid such as water at the extraction point thereof from a source such as a river.
One form of conventional filtration apparatus which is used for filtering water extracted from a source such as a river or estuary prior to utilising the water in an industrial process, fish farm or the like, comprises one or more stationary screens.
Objects in the water passing through the or each screen of such a filtration apparatus above a pre-set minimum size determined by the mesh size of the screens, are retained on the water input side of the screens. The collection of these objects on the input side of the or each screen reduces the flow of water therethrough and over a period of time dependent upon the level of contamination of the water being filtered and the mesh size of the screens, the reduction in flow reaches an unacceptable level or even complete blockage occurs.
In order to avoid blockage of the apparatus or an unacceptable reduction in the flow of water therethrough, it is necessary to either replace or clean the screens at frequent intervals.
It will be appreciated such conventional screen filtration apparatus suffers from the disadvantages that not only is the maintenance required a time consuming and therefore expensive operation, but also, if there is an unexpected deterioration in the quality of the input water, this can result in a complete blockage of the water supply and consequent damage to the process being supplied with water.
The object of this invention is to provide a filtration apparatus in which the above disadvantages are alleviated.
According to this invention, a filtration apparatus for filtering liquid comprises a hollow member adapted to be at least partially immersed in the liquid to be filtered; at least part of the surface portion of the member being formed of material which allows the passage of the liquid from the exterior to the interior of the member, whilst inhibiting the passage of objects in the liquid above a predetermined minimum size, so that filtered liquid is supplied from the interior of the member; wherein means is provided for moving the hollow member during the filtering operation to effect cleaning of said surface portion thereof.
Preferably, the hollow member is rotatable.
Preferably, also, the hollow member is cylindrical or substantially cylindrical and is rotatable about the longitudinal axis thereof.
At least part of the curved surface portion of the cylindrical member is, preferably, formed of a mesh type of material.
Preferably, one end face of the member is closed and the opposite end face has an opening to enable the filtered liquid to pass therethrough from the interior of the member.
Preferably, also, the means for moving the member during the filtering operation comprises an impeller mounted in the member to produce rotation of the member about the longitudinal axis thereof.
The impeller is, preferably, disposed at or adjacent to the open end of the member.
Preferably, the impeller comprises equi-angularly spaced-apart blades extending radially from the longitudinal axis of the member.
Preferably, also, the impeller is disposed within a duct formed by a plane section of the curved surface of the member.
The means for moving the member during the filtering operation, preferably, also comprises one or more vanes mounted on the internal face of the curved surface portion of the member, each extending longitudinally of the member and being angled so that the water passing through the member acts on the vanes to produce rotation of the member about the longitudinal axis thereof.
Preferably, each vane extends along a helix on the internal face of the curved surface portion of the member from the closed end to an associated one of the blades of the impeller.
Preferably, also, the impeller blades and/or the vanes are of an aerodynamic shape in cross-section.
The hollow member is, preferably, mounted in a channel or leat through which the liquid to be filtered flows so that said member extends transversely of the channel or leat.
Preferably, the member is provided with a longitudinally extending shaft, the ends of which project beyond the ends of the member and are journalled in bearings supported by the sides of the channel or leat to provide for rotation of the member.
Preferably, also, sealing means is provided between the open end of the member and the associated side of the channel or leat.
The hollow member can be supported by a modular structure comprising a box type frame of cross members which can be transported to site and dropped into an existing channel complete within the frame. However the frame can comprise only end plates and no cross channel members, the end plates supporting bearings for the hollow member and being bolted to the channel walls.
The frame can also comprise a modular structure with cross channel beams and end plates but with the end plates recessed into the channel walls. The end plates can be provided with covers in order to prevent debris accumulation within the recesses created.
The frames supporting the hollow member can also be provided with a weir either in the form of a vertical plate or with a streamlined plate angled up from the channel bed to the weir rim.
The surface of the hollow member can be formed in a number of ways. For example the surface of the hollow member can comprise an expanded metal mesh, eg. stainless steel which has been flattened and smoothed on the outside surface. Various hole shapes can be provided in the mesh ranging from circular to trapezoidal. The surface can also be in the form of a perforated metal mesh again stainless steel. The holes can be circular or to a specific shape.
The surface may be formed from a perforated sheet of plastics material eg. PVC. The perforations can be conical in section so that the hole diameters on opposing sides of the sheet differ as opposed to perforations formed by drilling or punching. The smaller diameter opening is formed on the dirty water side and the larger diameter opening is arranged to be on the inner clean water side.
The surface of the hollow member can be formed from a length of wire which is wedge shaped in section and wound helically around the hollow member. This provides a continuous slot which is narrow on the dirty water side and wider on the clean water side.
The vanes can be in the form of simple blades of metal or plastic of equal width and thickness throughout and fastened by means of lugs, screws, rivets, or bolts or are welded to the surface material of the hollow member on the inside of the hollow member.
Alternatively the metal or plastic blades forming the vanes can be of equal thickness throughout but varying in width between the ends of the hollow member. The vanes can be provided with a continuous foot and the foot can vary in width between one end of the vane and the other. The vane numbers and angles can be varied to suit a particularly set of circumstances. It will be noted that the vane curvature varies in direct proportion to the hollow member diameter.
The impeller shape can be aerodynamically profiled to give different angles of set, curvature and thickness according to specific requirements. A housing for the impellers can be either cylindrical or conical as required.
Sealing means can be in the form of a horizontal brush or can comprise a pliable blade of synthetic material.
The bearings on which the hollow member rotates can be formed from a self lubricating synthetic material with or without an anti-silt intrusion system. The anti-silt intrusion system can comprise a grease insertion channel and nipple which keeps the layer of grease around the shaft of the bearing and prevents intrusion of silt-laden water.
The bearings can also be ball or roller bearings in metal or synthetic material.
The filtration apparatus incorporates a self cleaning mechanism which can be aided by a pumped or a pressure spray of liquid on the downstream outer surface of the hollow member.
A weir is, preferably, mounted in the channel or leat on the downstream side of the member and extends substantially parallel but spaced-apart from the axis of rotation of the member.
Preferably, the depth of the weir below the surface of the liquid in the channel or leat is greater at the closed end of the member than at the open end thereof.
The invention further provides the filtration apparatus as described above positioned in a channel or leat. Flow controls are provided in the channel.
The flow controls can be located either upstream or downstream of the filtration apparatus.
A flow control upstream of the filtration apparatus can be arranged horizontally on the channel bed in the form of a "sleeping policeman" type of construction.
A flow control located downstream of the filtration apparatus can either by a vertical or horizontal control. A vertical control can be in the form of channel width restricters. A horizontal control can be in the form of an inclined smooth plane which may be curved to follow the contour of the screen drum of the filtration apparatus or simply angled upwardly from the horizontal bed of the channel or leat.
A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings of which:
Figure 1 is a diagrammatic side elevation of a channel or leat with a filtration apparatus disposed therein;
Figure 2 is a side elevation of a filter drum of the apparatus;
Figure 3 is a section on the line III-III in figure 2 of the drawings and;
Figure 4 is a diagrammatic perspective view of a unitary support structure for the filter drum with parts thereof shown in a dismantled condition for the sake of clarity.
Referring now to the drawings, filtration apparatus indicated generally at (10) for filtering water which is extracted from water flowing through a channel or leat (12) comprises a hollow cylindrical filter drum indicated generally at (14).
The filter drum (14) extends transversely across the channel or leat (12) and has a central longitudinally extending shaft (16).
The drum is preferably as circular as possible with no distortion and symmetrical about its central axis. Preferably the drum is balanced in the same manner as a vehicle wheel. The ends of the shaft (16)al process, fish farm or the like.
A major portion of the length of the curved surface of the drum (14) is formed of metal mesh (20) and the portion of the curved surface adjacent to the outlet end of the drum (14) is formed of plane sheet metal to form a duct portion (22).
It is found that metal mesh (20) having apertures therein each in the shape of a parallelogram or rhombus disposed with the major axis parallel to the shaft (16) about which the drum (14) is rotatable is particularly effective in deterring fish fry from passing therethrough.
Preferably at least 50% of the surface area of the drum is perforated and the ratio of perforated area to closed area of the drum should be at least 3.1. Preferably the ratio between the perforated area of the drum and the delivery area from the open end of the drum should be 3.25 to 1. These ratios are based upon 12/32 or 14/32 of the area of the open end of the drum being assumed as the ideal water level.
Six equi-angularly spaced-apart radially extending blades (24) are mounted on the shaft (16) within the duct portion (22). The end of each blade (24) remote from the shaft (16) is connected to one end of an associated vane (26) to the closed end of the drum (14) along the internal face of the curved surface thereof in a helical path.
The angle of the blade (24) and the helix of the vanes (26) are set to produce rotary motion of the drum (14) when acted upon by water flowing through the drum (14) and out of the open end thereof. The direction of rotation of the drum (14) is arranged so that the lower portion of the drum (14) which is immersed in the water moves in the direction of flow of the water in the channel or leat (12). The blades (24) and/or the vanes (26) are of an aerodynamic shape in cross-section to optimise the rotational force produced thereby on the drum (14).
The blades (24) which act as impellers are preferably six in number and equi-spaced around the drum periphery. The width of the impellers are preferably the same as the width of the duct portion (22) and are preferably angled at 450 to the centre line of the covered area of the drum (14) formed by the duct portion (22). The centre line of each impeller should be aligned upon centre line of the duct portion (22).
Preferably there are six vanes which are wound in a helix within the drum and the vane ends are welded or secured to the closed end of the drum and are set at an angle of approximately 32 from the horizontal. The ends of the vanes adjacent the open end of the drum are welded or otherwise secured to the blades (24). The width of each vane should be at least 10% of the screen diameter though the vane width can be varied longitudinally to suit local circumstances. The vanes can be either straight or curved or can have a water retention foot provided on them.
Sealing means in the form of brushes (28) are provided between the open end of the drum (14) and the side of the channel or leat (12) to prevent unfiltered water entering the drum (14) and being supplied thereform.
The brush seal should preferably set with bristle tips in contact with the outer surface of the duct portion (22) though they can also be set horizontally with the bristles lightly making contact with the circumference of the duct portion (22). In either case the bristle pressure is preferably adjustable.
A weir (30) is provided in the channel or leat (12) on the downstream side of the drum (14). The weir (30) extends across the channel or leat (12) in a direction substantially parallel to but spaced-apart from the axis of rotation of the drum (14).
The depth of the weir (30) below the surface of the water in the channel or leat (12) is greater at the end of the weir (30) adjacent to the closed end of the drum (14) than at the end of the weir (30) adjacent to the open end of the drum (14).
Referring now to figure 4 of the drawings, a unitary support structure indicated generally at (32) in which the drum (14) of the apparatus (10) is rotatably mounted comprises a lower subframe (34) and an upper sub-frame (36) which is releasably bolted thereto to allow insertion and/or removal of the drum (14) once the structure (32) has been installed.
The sides of the sub-frame (34) have the bearings (18) mounted thereon in which the ends of the shaft (16) are rotatably mounted. Mounting lugs (38) are provided on the sides and base of the sub-frame (34) adjacent the corners thereof by means of which the sub-frame (34) is secured in position in the channel or leat (12).
A face plate (40) is formed on the side of the structure (32) at the side of the channel or leat (12) from which water is to be drawn and the sealing brushes are mounted on at least the lower portion of the face plate (40).
A side deflector plate (42) is mounted on the opposite side of the structure to the face plate (40) to guide the water flow towards the area of the structure (32) occupied by the drum (14) and a base plate (44) having a deflector at the front end is mounted on the base of the structure (32) to also act as a guide for the flow of water.
The downstream side of the sub-frame (34) of the structure (32) has the weir (30) mounted thereon.
The weir (30) which acts as a stripping weir can be secured to the sub-frame (34) as described above or it can be mounted on separate vertical slides. The weir (30) is preferably set at a minimum distance equal to 10% of the drum diameter away from the down stream edge of the drum though the weir can be set at a much greater distance away to suit the local circumstances.
As has been described the upper edge of the weir is not level but is angled with the highest end of the weir being adjacent to the closed end of the drum. The angle of the weir top can be varied but an angle of 15 has been found to be suitable for most purposes.
The weir (30) is in the form of a vertical plate with the upper edge in the form of a blade with the thickness no greater than is necessary to impart rigidity across the width of the weir. The weir can be formed from two separate plates which are located in the same slot in a side by side relationship in order to provide a form of height adjustment for the weir.
The provision of the unitary support structure (32) in which the drum (14) is rotatably mounted facilitates the manufacture of the filter apparatus (10) on a conventional production line basis and minimises the on site work required to install the apparatus (10)
In operation, water from the channel or leat (12) enters the drum (14) of the filtration apparatus (10) through the mesh (20), flows along the interior of the drum (14), passes out of the open end thereof and is supplied to the industrial process, fish farm or the like.
Objects in the water above a size determined by the size of the mesh (20) are prevented from entering the drum (14) and a percentage of these objects remain on the external surface of the drum (14) whilst the remainder continue in the water flowing in the channel or leat (12) downstream of the drum (14).
The rotation of the drum (14) by the action of the filtered water flowing therethrough on the blades (24) and the vanes (26) continuously moves the curved surface thereof into the turbulent flow of water on the downstream side of the drum (14) which strips the objects from the surface of the mesh (20) and effects cleaning thereof.
The rotation of the drum (14) by the action of the filtered water flowing therethrough on the blades (24) and the vanes (26) continuously moves the curved surface thereof into the turbulent flow of water on the downstream side of the drum (14) which strips the objects from the surface of the mesh (20) and effects cleaning thereof.
The weir (30) increases the turbulence of the water flow on the downstream side of the drum (14) by increasing the velocity of the water flowing in the region of the closed end of the drum (14) which improves the cleaning action on the mesh (20).
In a modification, cleaning brushes or scrapers are provided which engage the external surface of the mesh (20) and effect cleaning thereof as the drum (14) rotates.
In a further modification, the drum (14) is drivably connected to a generator or mechanical power take-off mechanism so that the rotation of the drum (14) is utilised as a source of power.
In yet another modification, the drum (14) is drivably connected to a motor which is used to assist the rotation of the drum (14) during periods when the speed of rotation of the drum (14) produced by the water flowing therethrough falls below a predetermined minimum value required to effect efficient cleaning of the mesh (20).
As has been described the main frame (32) is normally a modular structure of a box type frame and cross members which can be transported to site and dropped into the existing hcannel complete within this frame. However the frame can comprise only end plates and no cross members, the end plates supporting the bearings for the hollow member and being bolted to the channel walls.
In another arrangement the frame can comprise a modular structure with cross channel members and end plates but with the end plates recessed into the channel walls and possibly having end covers fitted to prevent debris accumulation within the created recesses in the channel walls.
The weir can be incorporated into the frame in the form of a vertical plate or with a streamlined plate angled up from the channel bed to the weir rim.
The surface of the drum (14) can comprise an expanded metal mesh usually of stainless steel which has been flattened and smoothed on the outside surface. Various hole shapes from circular to trapezoidal can be provided.
The drum surface can also be formed from a perforated metal mesh again usually stainless steel in which circular holes, slots or holes to a specific shape can be provided.
The surface of the drum can also be formed from a perforated sheet made from a plastics material in which hole diameters of differing sizes on opposing sides of the sheet are formed, so that holes are conical in section rather than tubular as with drilled or punched holes. The smaller diameter holes are provided on the dirty water side of the drum and the larger diameter holes being on the inner cleaned water side.
In a further arrangement the drum surface can be provided by a continuous length of wire wound helically around the drum circumference, the wire being of a wedge shaped section. The slot formed by the wire winding is narrow on the dirty water side and wider on the clean water side.
The vanes (26) can be simple blades of metal or plastics material of equal width and thickness throughout fastened by means of lugs, screws, rivets, or bolts or welded to the surface material of the drum on the inside of the drum.
The vanes can be of equal thickness throughout but varying in width between the ends of the screen drum.
The vanes can be metal or plastic blades but with a continuous foot on the blades. The foot can vary in width between one end of the blade and the other.
The vane numbers and angles can be varied to suit a particular set of circumstances. Blade curvature varies in direct proportion to screen drum diameter.
The impellers are aerodynamically profiled giving different angles of set curvature and thickness according to a specific requirement. The impeller housing can be either cylindrical or conical as required.
The debris seals (28) can be in the form of horizontal brushes or can be in the form of pliable blades of synthetic material.
The bearings can be either ball or roller bearings in metal or synthetic material.
The self cleaning mechanism which has already been described above can be aided by pumped or a pressure spray of liquid on the downstream outer surface of the drum.
Although the apparatus is particularly suitable for continuously supplying filtered water to an industrial process, fish farm or the like whilst minimising the maintenance time required due to the self-cleaning action thereof, it will be appreciated the apparatus can be used in other applications such as sewage farm solid screening or as a salmon smolt screen in water turbine intakes without departing from the scope of this invention.
Flow controls can be provided in the channel or leat in which the screen is mounted either upstream or downstream of the screen.
The flow control upstream of the screen can be in the form of a "sleeping policeman" type installation on the bed of the channel.
This type of control installation enhances water flow patterns across the vanes in the screen.
Flow controls downstream of the screen can be vertical in the form of channel width restricters. The use of these restricters is suitable in channels with high debris load where any sort of weir would cause debris to drop out prematurely. Alternatively the flow controls can be horizontal in the form of an inclined smooth plane over which debris can be carried unimpeded. The plane may be curved to follow the contour of the screen drum or simply angled upwards from the horizontal.
Claims (37)
1. A filtration apparatus for filtering liquid comprising a
hollow member adapted to be at least partially immersed in
the liquid to be filtered; at least part of the surface
portion of the member being formed of material which allows
the passage of the liquid from the exterior to the interior
of the member, whilst inhibiting the passage of objects in
the liquid above a predetermined minimum size, so that
filtered liquid is supplied from the interior of the
member, wherein means is provided for moving the hollow
member during the filtering operation to effect cleaning of
said surface portion thereof.
2. An apparatus as claimed in claim 1 in which the hollow
member is rotatable.
3. An apparatus as claimed in claim 1 or claim 2 in which the
hollow member is cylindrical or substantially cylindrical
and rotatable about the longitudinal axis thereof.
4. An apparatus as claimed in claim 3 in which at least a part
of the curved surface portion of the cylindrical member is
formed of a mesh type of material.
5. An apparatus as claimed in any one of the preceding claims
in which at least one end face of the member is closed and
the opposite end face has an opening to enable the filtered
liquid to pass therethrough from the interior of the hollow
member.
6. An apparatus as claimed in claim 1 in which the means for
moving the member during the filtering operation comprises
an impeller mounted in the member to produce rotation of
the member about the longitudinal axis thereof.
7. An apparatus as claimed in claim 6 in which the impeller is
disposed at or adjacent to the open end of the member.
8. An apparatus as claimed in claim 6 or claim 7 in which the
impeller comprises equi-angularly spaced-apart blades
extending radially from the longitudinal axis of the
member.
9. An apparatus as claimed in either one of claims 6, 7 or 8
in which the impeller is disposed within a duct formed by
a plane section of the curved surface of the member.
10. An apparatus as claimed in claim 6 in which the means for
moving the member during the filtering operation preferably
further comprises one or more vanes mounted on the internal
face of the curved surface portion of the member, each vane
extending longitudinally of the member and being angled so
that the liquid passing through the member acts on the
vanes to produce rotation of the member about the
longitudinal axis thereof.
11. An apparatus as claimed in claim 10 in which each vane
extends along a helix on the internal face of the curved
surface portion of the member from the closed end to an
associated one of the blades of the impeller.
12. An apparatus as claimed in claim 10 in which the impeller
blades and or the vanes are of an aerodynamic shape in
cross-section.
13. An apparatus as claimed in claim 1 in which the hollow
member is preferably mounted in a channel or leat through
which the liquid to be filtered flows so that said member
extends transversely of the channel or leat.
14. An apparatus as claimed in claim 13 in which the member is
provided with a longitudinally extending shaft the ends of
which project beyond the ends of the member and are
journalled in bearings supported by the sides of the
channel or leat to provide for rotation of the member.
15. An apparatus as claimed in claim 1 in which sealing means
is provided between the open end of the member and the
associated side of the channel or leat.
16. An apparatus as claimed in any one of the preceding claims
in which the hollow member can be supported by a modular
structure comprising a box type frame of cross members
which can be transported to site and dropped into an
existing channel complete within the frame.
17. An apparatus as claimed in any one of the preceding claims
1 to 15 in which the hollow member can be supported by a
box type frame comprising end plates supporting bearings
for the hollow member and being bolted to walls of the
channel of leat.
18. An apparatus as claimed in any one of the preceding claims
1 to 15 in which the hollow member can be supported by a
modular structure comprising a box type frame of cross
beams and end plates, the end plates being recessed into
the walls of the channel or leat.
19. An apparatus as claimed in claim 18 in which the end plates
are provided with covers in order to prevent debris
accumulation within the recesses created.
20. An apparatus as claimed in any one of the preceding claims
13 to 19 in which the frame supporting the hollow member
can also be provided with a weir either in the form of a
vertical plate or with a streamline plate angled up from
the channel bed to the weir rim.
21. An apparatus as claimed in any one of the preceding claims
in which the surface of the hollow member can comprise an
expanded metal mesh, eg stainless steel which has been
flattened and smoothed on the outside surface.
22. An apparatus as claimed in claim 21 in which the holes in
the mesh can be circular or polygonal.
23. An apparatus as claimed in any one of the preceding claims
1 to 21 in which the surface of the hollow member is in the
form of a perforated metal mesh, eg stainless steel.
24. An apparatus as claimed in claim 23 in which the holes are
circular or polygonal.
25. An apparatus as claimed in claim 1 in which perforations in
the hollow member can be conical in section so that the
hole diameters on opposing sides of the sheet differ, the
smaller diameter opening being formed on the dirty liquid
side and the larger diameter side being arranged to be on
the inner clean liquid side.
26. An apparatus as claimed in claim 1 in which the surface of
the hollow member is formed from a length of wire which is
wedged shape in section and wound helically around the
hollow member in order to provide a continuous slot which
is narrow on the dirty liquid side and wider on the clean
liquid side.
27. An apparatus as claimed in claim 10 in which the vanes are
in the form of simple blades of metal or plastics material
of equal width and thickness throughout and fastened in
position by means of lugs or screws or rivets or bolts, or
are welded to the surface material of the hollow member or
the inside of the hollow member.
28. An apparatus as claimed in claim 10 in which the metal or
plastic blades forming the vanes can be of equal thickness
throughout but varying in width between the ends of the
hollow member.
29. An apparatus as claimed in claim 28 in which the vanes are
provided with a continuous foot and the foot can vary in
width between one end of the vane and the other.
30. An apparatus as claimed in claim 10 in which the vane
curvature varies in direct proportion to the diameter of
the hollow member.
31. An apparatus as claimed in claim 6 in which the impeller
shape can be aerodynamically profiled to give different
angles of set curvature and thickness according to the
requirements of the apparatus.
32. An apparatus as claimed in claim 6 in which the housing for
the impeller can be either cylindrical or conical.
33. An apparatus as claimed in claim 15 in which the sealing
means can be in the form of a horizontal brush or can
comprise a pliable blade of synthetic material.
34. An apparatus as claimed in claim 1 including bearings on
which the hollow member rotates the bearings being formed
from a self lubricating synthetic material with or without
an anti-silt intrusion system.
35. An apparatus as claimed in claim 34 in which the anti-silt
intrusion system comprises a grease insertion channel and
nipple which maintains a layer of grease around the shaft
of the bearing and prevents intrusion of silt laden liquid.
36. An apparatus as claimed in claim 1 including a self
cleaning mechanism which can be aided by a pumped or a
pressure spray of liquid on the downstream outer surface of
the hollow member.
37. A filtration apparatus constructed and arranged for use and
operation, substantially as herein described, and with
reference to the accompanying drawings.
37. A filtration apparatus as claimed in any one of the
preceding claims mounted in a channel or leat, the channel
or leat including a weir mounted preferably on the
downstream side of the hollow member and extending
substantially parallel but spaced apart from the axis or
rotation of the member.
38. An apparatus as claimed in claim 37 in which the depth of
the weir below the surface of the liquid in the channel or
leat is greater at the closed end of the member than at the
open end thereof.
39. A filtration apparatus constructed and arranged for use and
operation, substantially as herein described, and with
reference to the accompanying drawings.
Claims 1. A filtration apparatus for filtering liquid comprising a
hollow member adapted to be at least partially immersed in
the liquid to be filtered; the hollow member being closed
at one end and open at the opposite end, at least part of
the surface portion of the member being formed of material
which allows the passage of the liquid from the exterior to
the interior of the member, whilst inhibiting the passage
of objects in the liquid above a predetermined minimum
size, so that filtered liquid is supplied from the interior
of the member, means being provided for moving the hollow
member during the filtering operation to effect cleaning of
said surface portion thereof, the said means comprising an
impeller mounted in the member to produce rotation of the
member about the longitudinal axis thereof, the impeller
comprising spaced-apart blades extending radially from the
longitudinal axis of the member.
2. An apparatus as claimed in claim 1 in which the hollow
member is rotatable.
3. An apparatus as claimed in claim 1 or claim 2 in which the
hollow member is cylindrical or substantially cylindrical
and rotatable about the longitudinal axis thereof.
4. An apparatus as claimed in claim 3 in which at least a part
of the curved surface portion of the cylindrical member is
formed of a mesh type of material.
5. An apparatus as claimed in any one of the preceding claims
in which at least one end face of the member is closed and
the opposite end face has an opening to enable the filtered
liquid to pass therethrough from the interior of the hollow
member.
6. An apparatus as claimed in claim 1 in which the impeller is
disposed at or adjacent to the open end of the member.
7. An apparatus as claimed in any one of the preceding claims
in which the impeller is disposed within a duct formed by
a plane section of the curved surface of the member.
8. An apparatus as claimed in claim 1 in which the means for
moving the member during the filtering operation preferably
further comprises one or more vanes mounted on the internal
face of the curved surface portion of the member, each vane
extending longitudinally of the member and being angled so
that the liquid passing through the member acts on the
vanes to produce rotation of the member about the
longitudinal axis thereof.
9. An apparatus as claimed in claim 8 in which each vane
extends along a helix on the internal face of the curved
surface portion of the member from the closed end to an
associated one of the blades of the impeller.
10. An apparatus as claimed in claim 8 in which the impeller
blades and or the vanes are of an aerodynamic shape in
cross-section.
11. An apparatus as claimed in claim 1 in which the hollow
member is preferably mounted in a channel or leat through
which the liquid to be filtered flows so that said member
extends transversely of the channel or leat.
12. An apparatus as claimed in claim 12 in which the member is
provided with a longitudinally extending shaft the ends of
which project beyond the ends of the member and are
journalled in bearings supported by the sides of the
channel or leat to provide for rotation of the member.
13. An apparatus as claimed in claim 1 in which sealing means
is provided between the open end of the member and the
associated side of the channel or leat.
14. An apparatus as claimed in any one of the preceding claims
in which the hollow member can be supported by a modular
structure comprising a box type frame of cross members
which can be transported to site and dropped into an
existing channel complete within the frame.
15. An apparatus as claimed in any one of the preceding claims
1 to 13 in which the hollow member can be supported by a
box type frame comprising end plates supporting bearings
for the hollow member and being bolted to walls of the
channel of leat.
16. An apparatus as claimed in any one of the preceding claims
1 to 13 in which the hollow member can be supported by a
modular structure comprising a box type frame of cross
beams and end plates, the end plates being recessed into
the walls of the channel or leat.
17. An apparatus as claimed in claim 16 in which the end plates
are provided with covers in order to prevent debris
accumulation within the recesses created.
18. An apparatus as claimed in any one of the preceding claims
11 to 17 in which the frame supporting the hollow member
can also be provided with a weir either in the form of a
vertical plate or with a streamline plate angled up from
the channel bed to the weir rim.
19. An apparatus as claimed in any one of the preceding claims
in which the surface of the hollow member can comprise an
expanded metal mesh, eg stainless steel which has been
flattened and smoothed on the outside surface.
20. An apparatus as claimed in claim 19 in which the holes in
the mesh can be circular or polygonal.
21. An apparatus as claimed in any one of the preceding claims
1 to 19 in which the surface of the hollow member is in the
form of a perforated metal mesh, eg stainless steel.
22. An apparatus as claimed in claim 21 in which the holes are
circular or polygonal.
23. An apparatus as claimed in claim 1 in which perforations in
the hollow member can be conical in section so that the
hole diameters on opposing sides of the sheet differ, the
smaller diameter opening being formed on the dirty liquid
side and the larger diameter side being arranged to be on
the inner clean liquid side.
24. An apparatus as claimed in claim 1 in which the surface of
the hollow member is formed from a length of wire which is
wedged shape in section and wound helically around the
hollow member in order to provide a continuous slot which
is narrow on the dirty liquid side and wider on the clean
liquid side.
25. An apparatus as claimed in claim 8 in which the vanes are
in the form of simple blades of metal or plastics material
of equal width and thickness throughout and fastened in
position by means of lugs or screws or rivets or bolts, or
are welded to the surface material of the hollow member or
the inside of the hollow member.
26. An apparatus as claimed in claim 8 in which the metal or
plastic blades forming the vanes can be of equal thickness
throughout but varying in width between the ends of the
hollow member.
27. An apparatus as claimed in claim 26 in which the vanes are
provided with a continuous foot and the foot can vary in
width between one end of the vane and the other.
28. An apparatus as claimed in claim 8 in which the vane
curvature varies in direct proportion to the diameter of
the hollow member.
29. An apparatus as claimed in claim 1 in which the impeller
shape can be aerodynamically profiled to give different
angles of set curvature and thickness according to the
requirements of the apparatus.
30. An apparatus as claimed in claim 1 in which the housing for
the impeller can be either cylindrical or conical.
31. An apparatus as claimed in claim 13 in which the sealing
means can be in the form of a horizontal brush or can
comprise a pliable blade of synthetic material.
32. An apparatus as claimed in claim 1 including bearings on
which the hollow member rotates the bearings being formed
from a self lubricating synthetic material with or without
an anti-silt intrusion system.
33. An apparatus as claimed in claim 34 in which the anti-silt
intrusion system comprises a grease insertion channel and
nipple which maintains a layer of grease around the shaft
of the bearing and prevents intrusion of silt laden liquid.
34. An apparatus as claimed in claim 32 including a self
cleaning mechanism which can be aided by a pumped or a
pressure spray of liquid on the downstream outer surface of
the hollow member.
35. A filtration apparatus as claimed in any one of the
preceding claims mounted in a channel or leat, the channel
or leat including a weir mounted preferably on the
downstream side of the hollow member and extending
substantially parallel but spaced apart from the axis or
rotation of the member.
36. An apparatus as claimed in claim 35 in which the depth of
the weir below the surface of the liquid in the channel or
leat is greater at the closed end of the member than at the
open end thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9414498A GB2279889B (en) | 1993-07-17 | 1994-07-18 | Filtration apparatus |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB939314948A GB9314948D0 (en) | 1993-07-17 | 1993-07-17 | Filtration apparatus |
| GB939325845A GB9325845D0 (en) | 1993-12-17 | 1993-12-17 | Filtration apparatus ii |
| GB9414498A GB2279889B (en) | 1993-07-17 | 1994-07-18 | Filtration apparatus |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9414498D0 GB9414498D0 (en) | 1994-09-07 |
| GB2279889A true GB2279889A (en) | 1995-01-18 |
| GB2279889B GB2279889B (en) | 1997-03-12 |
Family
ID=27266781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9414498A Expired - Fee Related GB2279889B (en) | 1993-07-17 | 1994-07-18 | Filtration apparatus |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2279889B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2309398A (en) * | 1996-01-23 | 1997-07-30 | Thames Water Utilities | Self-cleaning flow-powered rotary drum |
| GB2315684A (en) * | 1996-07-29 | 1998-02-11 | United Utilities Plc | A self-cleaning filter system |
| WO1999039805A1 (en) * | 1998-02-05 | 1999-08-12 | Schenk Filterbau Gesellschaft mit beschränkter Haftung | Filtration member for solid-liquid separation |
| GB2370999A (en) * | 2001-01-11 | 2002-07-17 | Mono Pumps Ltd | A screening device with a rotating cleaning member |
| WO2003022399A1 (en) * | 2001-09-12 | 2003-03-20 | Copa Limited | Filtering apparatus |
| CN104941290A (en) * | 2015-06-29 | 2015-09-30 | 蚌埠市现代环保设备有限公司 | Efficient impurity removal device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB851648A (en) * | 1957-12-23 | 1960-10-19 | Improved Machinery Inc | Improvements in filters |
| GB1238742A (en) * | 1969-08-29 | 1971-07-07 | ||
| US3622006A (en) * | 1969-10-20 | 1971-11-23 | Marc M Brunner | Self-cleaning strainer for pipeline |
| US3876548A (en) * | 1972-06-22 | 1975-04-08 | Hydrocyclonics Corp | Screening method and apparatus |
| US4017394A (en) * | 1975-05-12 | 1977-04-12 | Hensley Roy A | Water screen |
| US4053413A (en) * | 1975-11-17 | 1977-10-11 | Miller John M | Apparatus for removing particles from water for sprinklers and the like |
-
1994
- 1994-07-18 GB GB9414498A patent/GB2279889B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB851648A (en) * | 1957-12-23 | 1960-10-19 | Improved Machinery Inc | Improvements in filters |
| GB1238742A (en) * | 1969-08-29 | 1971-07-07 | ||
| US3622006A (en) * | 1969-10-20 | 1971-11-23 | Marc M Brunner | Self-cleaning strainer for pipeline |
| US3876548A (en) * | 1972-06-22 | 1975-04-08 | Hydrocyclonics Corp | Screening method and apparatus |
| US4017394A (en) * | 1975-05-12 | 1977-04-12 | Hensley Roy A | Water screen |
| US4053413A (en) * | 1975-11-17 | 1977-10-11 | Miller John M | Apparatus for removing particles from water for sprinklers and the like |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2309398A (en) * | 1996-01-23 | 1997-07-30 | Thames Water Utilities | Self-cleaning flow-powered rotary drum |
| GB2315684A (en) * | 1996-07-29 | 1998-02-11 | United Utilities Plc | A self-cleaning filter system |
| WO1999039805A1 (en) * | 1998-02-05 | 1999-08-12 | Schenk Filterbau Gesellschaft mit beschränkter Haftung | Filtration member for solid-liquid separation |
| DE19804493B4 (en) * | 1998-02-05 | 2008-03-27 | Pall Corp. | Filter medium for solid / liquid separation |
| GB2370999A (en) * | 2001-01-11 | 2002-07-17 | Mono Pumps Ltd | A screening device with a rotating cleaning member |
| WO2003022399A1 (en) * | 2001-09-12 | 2003-03-20 | Copa Limited | Filtering apparatus |
| GB2398027A (en) * | 2001-09-12 | 2004-08-11 | Copa Ltd | Filtering apparatus |
| GB2398027B (en) * | 2001-09-12 | 2005-11-23 | Copa Ltd | Filtering apparatus |
| US7150826B2 (en) | 2001-09-12 | 2006-12-19 | Copa Limited | Filtering apparatus |
| CN104941290A (en) * | 2015-06-29 | 2015-09-30 | 蚌埠市现代环保设备有限公司 | Efficient impurity removal device |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2279889B (en) | 1997-03-12 |
| GB9414498D0 (en) | 1994-09-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19990718 |