Gravity flow filter with backwash control chamber
OwnerChristopher R. Schulzinventor
Life of this patent
Estimating the term…
Abstract
A gravity flow, single or multi-cell filter incorporating an integral backwash control chamber for enabling backwashing to occur without the need for backwash pumps. The backwash control chamber contains a volume of backwash liquid, and communicates with a source of pressurized backwash liquid through a float-controlled flow control valve in order to maintain a desired liquid level within the backwash control chamber during backwashing operations. The flow of backwash liquid from the backwash control chamber is controllable either by means of three-way valves interconnecting the backwash control chamber with the filter outlet chamber, or by wash water control gates within the backwash chamber that are adapted to selectively cover outlet openings to permit backwash flow to enter the filter outlet chamber.
Claims12
A gravity flow, liquid filter comprising:
- a) a vessel including a liquid inlet conduit for conducting unfiltered liquid from a source of unfiltered liquid to the vessel, and a liquid outlet conduit for conducting filtered liquid from the vessel to a downstream clearwell;
- b) a filter cell positioned within the vessel for receiving liquid to be filtered that enters the vessel through the liquid inlet, the filter cell including a filter bed and having a liquid outlet communicating with the vessel outlet;
- c) a backwash chamber in communication with a source of filtered backwash liquid and with the filter cell, the backwash chamber positioned to provide a backwash liquid level at a higher elevation than liquid within the filter cell to permit gravity flow of the backwash liquid from the backwash chamber to the liquid outlet of the filter cell to flow through the filter cell in a reverse direction relative to flow of unfiltered liquid through the filter cell to clean the filter cell of accumulated filtrate material during a filter cell backwash operation;
- d) a first backwash liquid flow control valve communicating with the backwash chamber for providing backwash liquid from a pressurized backwash liquid source to the backwash chamber, the backwash flow control valve operatively connected with a liquid level sensor responsive to a backwash liquid level within the backwash chamber for maintaining a desired level of backwash liquid within the backwash chamber;
- e) a second backwash flow conduit extending between the backwash chamber and the liquid outlet of the filter cell, the backwash flow conduit including a backwash flow control valve for selectively controlling the rate of flow of backwash liquid from the backwash chamber to the filter cell for permitting backwash liquid to flow through the filter cell during a backwash operation in a reverse direction relative to flow through the filter bed of liquid to be filtered during a filtering operation;
- and
- f) a drain conduit extending from the vessel for receiving backwash liquid after the backwash liquid has passed through the filter bed and for conveying the backwash flow to a drain line.
Dependencies are inferred from the claim text.