Patent Application
20110192773
This invention relates to the fields of water filtration systems and storm water control systems.
The present invention is designed to control and filter runoff water in storm drains. Drain water frequently carries trash, organic matter, suspended solids, hydrocarbons, metals, nutrients and bacteria is collected from paved surfaces and other areas into a storm drain inlet, then sent into a storm water drain pipe system. Drain water often carries oil collected from the streets.
Various water bodies including ponds, rivers, and oceans can tolerate a certain amount of pollutant loading, but the amount allowed to flow into these collection areas should be minimized. The present invention is a in-line storm water drain filter system having with a series of separation chambers for removing larger material followed by an upflow filter for smaller and dissolved material. The filter box is installed within a storm water drain pipe; this pipe directs drain water through the separation chambers and up flow filter to the storm water drain water passing through an outfall into a lake, pond or retention area. There is an upflow filter between the separation chambers and the outflow to address collection of fine particulates and organics. A hydrocarbon collecting boom in a cage is placed at the last separation baffle on the influent side to absorb hydrocarbons.
The inline partitioned separator and upflow filter system is installed inline with the drain water flow path, and can be buried underground with access ports. The filter system includes a housing having an inlet and an outlet and a plurality of separation chambers formed therein. The separation chambers collect various densities of sediment for later cleaning. A housing cover allows access into the housing and a plurality of separation chambers and media cages.
An oil collection boom is removably mounted on one or more of the baffles near the outlet for collecting hydrocarbons in the drain water entering the system.
The separation chambers closest to the outflow are each equipped with an up flow filter. The up flow filter has two main components: the filter housing and the filter media. The filter housing is constructed of a cage that holds the media. It has top doors that open to allow the media to be changed out.
The media is a filter that removes fine TSS, nutrients, metals, bacteria, and emulsified hydrocarbons from the drain water as it flows upward through the last separation chamber.
One of the unique features of this system is that fall between the inflow and outflow pipes is not necessary as with downward flow systems. The internal weir, located on the side of the up flow filter opposite of the outflow pipe allows water pressure to build behind it which drives water through the up flow filter.
A standard 3 chambered separator works well enough to provide the necessary drain water pretreatment to prevent larger particles and solid pollutants from prematurely clogging the up flow filter.
The invention consists of a rectangular box 101 inserted in the flow stream of a drain 102 with an inflow end 103 and an outflow end 104. The box 101 is divided into a plurality of separation chamber compartments 105 with no tops, the tops of the compartments 105 open to the air.
The compartments 105 are designed to trap sediment as it flows from the inflow 103, as shown in
In the preferred embodiment, the last baffled compartment 110 possesses a hydrocarbon-absorbing boom 111 and an upflow filter 107. Water rising from the last compartment 110 leaves through the outflow end 104 due to water pressure formed in the last compartment 110 and is forced up through the filter 107, which is designed to remove fine and dissolved pollutants from the drain water.
An alternate embodiment uses a float and a gate to direct all overflow water over the last baffle when drain water levels are high, closing the last separation chamber 110. This effectively bypasses the media filter 107 during storm conditions but still allows the absorbent boom 111 to be effective.
The apparatus and methods described are the preferred and alternate embodiments of this invention, but other methods are possible and are within the contemplation of this patent.
