Up-flow rake bar screen
OwnerDavid P Froudinventor
Life of this patent
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Abstract
The present invention relates to an up-flow rake bar screen having a multiplicity of bars which are parallel to one another and which are spaced from one another across the screen. At least a portion of each bar is curved so that, when that portion is viewed from a position at which, when the screen is in use, fluid has not yet passed through the screen, that portion of the bar appears convex.
Claims17
An up-flow rake bar screen assembly comprising an up-flow rake bar screen (10) having a multiplicity of bars (14) which are parallel to one another and which are spaced from one another across the screen (10), together with a rake (18 or 20) having a multiplicity of blades (22 or 24) which extend between the bars (14) of the screen (10), in which the rake (18 or 20) is provided with drive means (16) to move the blades (22 or 24) to and fro longitudinally of the bars (14), in which at least a portion of each bar (14) is curved so that, when that portion is viewed from a position at which, when the screen is in use, fluid has not yet passed through the screen (10), that portion of the bar (14) is convex, characterised in that the rake (18 or 20) is track guided, and in that the drive means (16) are arranged above the screen (10) and the rake (18 or 20) extends downwardly from the drive means (16).
An up-flow rake bar screen assembly according to any preceding claim, characterised in that each bar (14) has at least two curves spaced apart longitudinally of the bar (14) with voids or open spaces or pockets provided at the ends of the curves.
An up-flow rake bar screen assembly according to any preceding claim, characterized in that the blades (22 or 24) are tapered in a downward direction.
An up-flow rake bar screen assembly according to any preceding claim, characterised in that the blades (22 or 24) have rounded lowermost ends.
A sewage system overflow installation comprising an assembly in accordance with any preceding claim.
A method of filtering sewage during storm overflow conditions in which the sewage is passed through an up-flow rake bar screen (10) comprising a multiplicity of bars (14) which are parallel to one another and which are spaced from one another across the screen (10), at least portions of the bars (14) being curved so that those portions are convex to the approaching sewage, and moving a rake (18 or 20) having a multiplicity of blades (22 or 24) which extend between the bars (14) of the screen (10) so that the blades (22 or 24) move to and fro longitudinally of the bars (14), characterised in that the rake (18 or 20) is guided by track, and in that the rake (18 or 20) is moved by drive means (16) arranged above the screen (10) and the rake (18 or 20) extends downwardly from the drive means (16).
Dependencies are inferred from the claim text.