Patent ID: 8658044
Filing Date: 2014-02-25
Classification: C02F,E03F

Abstract:
1. A filter cartridge for removing pollutants from stormwater, comprising: a housing having a water inlet and a filtered water outlet; a filter medium disposed along a flow path between the water inlet and the filtered water outlet; a drainage space that forms at least part of the flow path and that is disposed between a downstream side of the filter medium and the filtered water outlet; a solid wall float tube disposed in the drainage space and having an open lower end and open upper end to allow air to pass into, upward through and out of the tube into the drainage space, the solid wall float tube movable between a lowered position that inhibits or substantially restricts filtered water at the bottom of the drainage space from passing to the filtered water outlet and a raised position that permits free flow of filtered water to the filtered water outlet; a fluid reservoir in fluid communication with the drainage space and disposed within the housing and above the filter medium for collecting filtered water as water level in the housing rises while the solid wall float tube is in the lowered position; wherein, as the housing fills, water level in the housing rises to cause the solid wall float tube to move to the raised position and a negative pressure can be established in the housing that draws fluid through the filter medium; wherein, as water level outside the filter cartridge drops, air enters the housing via the water inlet and causes the solid wall float tube to drop to the lowered position, and filtered water in the fluid reservoir backflows through the filter medium and out of the housing through the water inlet while air enters the housing by passing upward through the solid wall float tube so as to enhance rate of backflow while the solid wall float tube is in the lowered position.