A liquid filter device can filter liquid flowing therethrough using a granulated filter media included in a tank. The liquid filter device can perform a backwash of the granulated filter media by creating active zones and inactive zones in the tank. In the active zones, the granules are agitated and driven by a flow of liquid toward the top of the tank. In the inactive zones, the granules fall by gravity toward the bottom of the tank. The liquid filter device can include a conduit, a hub and a number of laterals, each of which may individual fit through an opening in the tank and be assembled to form a combined structure that will not fit through the opening in the tank. The active zones may be created above a top surface of each of the laterals by including slots on the top surface.

A liquid filter device can filter liquid flowing therethrough using a granulated filter media included in a tank. The liquid filter device can perform a backwash of the granulated filter media by creating active zones and inactive zones in the tank. In the active zones, the granules are agitated and driven by a flow of liquid toward the top of the tank. In the inactive zones, the granules fall by gravity toward the bottom of the tank. The liquid filter device can include a conduit, a hub and a number of laterals, each of which may individual fit through an opening in the tank and be assembled to form a combined structure that will not fit through the opening in the tank. The active zones may be created above a top surface of each of the laterals by including slots on the top surface.

An underdrain block for filtering water includes a top wall, a bottom wall, and two side walls connecting the top wall to the bottom wall to define an internal chamber. The bottom wall contains a plurality of orifices that allow liquid and solid materials to enter and exit the internal chamber. An underdrain filtering system can be formed by securing an underdrain lateral, which is formed from one or a plurality of underdrain blocks, to a filter floor. Also included is a method of preparing an underdrain lateral for providing even distribution of backwash water along the underdrain lateral and a method of validating even distribution of backwash water across an underdrain lateral.

An underdrain block for filtering water includes a top wall, a bottom wall, and two side walls connecting the top wall to the bottom wall to define an internal chamber. The bottom wall contains a plurality of orifices that allow liquid and solid materials to enter and exit the internal chamber. An underdrain filtering system can be formed by securing an underdrain lateral, which is formed from one or a plurality of underdrain blocks, to a filter floor. Also included is a method of preparing an underdrain lateral for providing even distribution of backwash water along the underdrain lateral and a method of validating even distribution of backwash water across an underdrain lateral.

A method and an apparatus for treating a liquid containing impurities may include a filtering chamber configured to permit granular media to interact with liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section for receiving the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; a reject section in fluid communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer; and a control unit that is configured to determine whether the portion of the granular media is being transported properly based on an amount of reject mixture in the reject section.

A method and an apparatus for treating a liquid containing impurities may include a filtering chamber configured to permit granular media to interact with liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section for receiving the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; a reject section in fluid communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer; and a control unit that is configured to determine whether the portion of the granular media is being transported properly based on an amount of reject mixture in the reject section.

The present disclosure a mechanical filter element (2) for forming a static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter element (1) has one or more filter cell (19). The present disclosure also relates to a mechanical filter apparatus (1) having a filter chamber (10) containing a plurality of mechanical filter elements (2) for forming the static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter apparatus (1) is configured to generate a flow of the liquid through the mechanical filter elements (2) during filtration to form the static filter pack (11). Furthermore, the present disclosure relates to a method of mechanically filtering a liquid. A plurality of mechanical filter elements (2) each comprising one or more filter cell (19) are disposed in a filter chamber (10). During filtration, the liquid flows through the filter chamber (10) to establish a static filter pack (11) of said mechanical filter elements (2) to mechanically filter the liquid.

The present disclosure a mechanical filter element (2) for forming a static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter element (1) has one or more filter cell (19). The present disclosure also relates to a mechanical filter apparatus (1) having a filter chamber (10) containing a plurality of mechanical filter elements (2) for forming the static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter apparatus (1) is configured to generate a flow of the liquid through the mechanical filter elements (2) during filtration to form the static filter pack (11). Furthermore, the present disclosure relates to a method of mechanically filtering a liquid. A plurality of mechanical filter elements (2) each comprising one or more filter cell (19) are disposed in a filter chamber (10). During filtration, the liquid flows through the filter chamber (10) to establish a static filter pack (11) of said mechanical filter elements (2) to mechanically filter the liquid.

A particulate filtering device with a multi-layer water distribution and collection structure and a method for using the same are provided. The device includes a tank where a filtering space and a back flushing expansion space are formed. An upper water distribution pipe is arranged above the back flushing expansion space and is in communication with an ozone gas-water mixing pipe. Ozone enters the back flushing expansion space through the upper water distribution pipe and mix with water for reaction. Exhaust gas is discharged from the top of the tank. Powdered activated carbon may enter the tank through the upper water distribution pipe, and is intercepted at a space above the filtering space to form an activated carbon layer, to absorb organics dissolved in the water and catalytically decompose ozone. At least three water distribution and collection pipes are arranged on a layer basis in the filtering space.

A particulate filtering device with a multi-layer water distribution and collection structure and a method for using the same are provided. The device includes a tank where a filtering space and a back flushing expansion space are formed. An upper water distribution pipe is arranged above the back flushing expansion space and is in communication with an ozone gas-water mixing pipe. Ozone enters the back flushing expansion space through the upper water distribution pipe and mix with water for reaction. Exhaust gas is discharged from the top of the tank. Powdered activated carbon may enter the tank through the upper water distribution pipe, and is intercepted at a space above the filtering space to form an activated carbon layer, to absorb organics dissolved in the water and catalytically decompose ozone. At least three water distribution and collection pipes are arranged on a layer basis in the filtering space.