Screening apparatus for water treatment with membranes
OwnerPierre Cote, Doug Thompson +4inventors
InventorsPierre Cote, Doug Thompson, Jennifer Pawloski, Minggang Liu, Rafael Simon, Ali Adnan
Life of this patent
Estimating the term…
Abstract
A static screen used upstream of a membrane assembly within a water treatment system has a screening surface with a number of openings distributed over its area. Liquid flows through the screening surface to reach the membrane assembly. Various shapes of screening surfaces are described including undulating panels and geometric shapes. Methods for cleaning the screen are described including aeration and backwashing. Various treatment systems or process designs incorporating the screen are described.
Claims29
A screening apparatus for use in a water treatment system having an upstream area under ambient pressure with a first static head and a downstream area under ambient pressure with a second static head, the screening apparatus comprising:
- one or more generally static screening surfaces having a plurality of openings, wherein any dimension of the openings is approximately 3 mm or less;
- a structure for holding the screening surface in communication with the upstream and downstream areas such that the screening surface intercepts water flowing between the upstream and downstream areas;
- and,
- a device that produces gas bubbles in the upstream area.
An apparatus comprising:
- one or more fluidly connected tanks;
- an inlet to the one or more tanks;
- a membrane assembly immersed in one of the tanks;
- a static screen separating a volume of water containing the membrane assembly from the inlet;
- a permeate outlet connected to the membrane assembly;
- and,
- a membrane retentate outlet in communication with the volume of water containing the membrane assembly.
A process for treating water comprising the steps of:
- a) flowing water containing undesirable solids, the undesirable solids being at least 20 μm wide in any direction, through a generally stationary screening surface in a forward direction from an upstream side of the screening surface to a downstream side of the screening surface, the flow of the water driven substantially by the difference between a static head in communication with the upstream side of the screening surface and a lesser static head in communication with the downstream side of the screening surface;
- and,
- b) stopping the flow of water through the screen in the forward direction from time to time and removing undesirable solids from the upstream side of the screening surface while the flow of water through the screen in the forward direction is stopped.
Dependencies are inferred from the claim text.