A sea strainer can include multiple strainers in a configuration for operation to supply strained sea water to a vessel's engines and to perform backflushing of one of the strainers while another of the strainers continues to provide strained sea water to the vessel's engines. A flush pump can be provided to pump water through the strainer to be backflushed as part of the flushing operation.

A system for filtering fluids includes a primary filter (2) having at least one filter element that can be penetrated in one direction during the filtration process and can be penetrated in the opposite direction for a backflushing process. An aftertreatment device (36) is mounted downstream of the primary filter (2) for the backflushed quantities discharged by the primary filter to be processed and includes at least one filter chamber (11) that holds the backflushed quantities and that has a fluid inlet, a fluid outlet and at least one aftertreatment filter element (19). A control device (9) delivers one portion of the backflushed quantity at a time to the associated aftertreatment filter element (19).

This specification describes an intake filter for use, for example, in a system that collects greywater from baths or showers for re-use in toilet flushing. The intake filter provides essentially dead-end filtration. An influent by-pass may be provided, but the filter is cleaned as required to reduce use of the by-pass. Cleaning is performed when permeability of the filter declines. An upstream sensor may be used to detect the permeability of the filter. In one cleaning method, flowing water, optionally with air, is used to backwash the filter. The impulse of the flowing water also moves one or more valves to direct backwash water to a sanitary drain. For example, pumped effluent may impinge against a first flap to close an effluent drain, the first flap being mechanically linked to open a flap covering the sanitary drain.

A variable pore size filter media including an upper plate, a retainer, and a support profile disposed between the upper plate and the retainer. The variable pore size filter media also includes a plurality of wire rings disposed on the support profile and longitudinally distributed within a region between the upper plate and the retainer, the plurality of wire rings being distributed in a non-contiguous manner to form a plurality of spaces therebetween. The variable pore size filter media further includes a plurality of pores defined by the plurality of spaces between the plurality of wire rings and a pore size adjustment mechanism configured to vary a respective distance between each of the plurality of wire rings to increase or decrease a respective size of each of the plurality of pores by increasing or decreasing a size of each of the plurality of spaces.

A pond filter unit and a method for operating a pond filter unit is provided. A control unit controls the operation of the pond filter unit, including the cleaning cycle of the filter. The pond filter unit further includes one or more plugs for connecting one or more auxiliary devices, such as a separate pump, one or more additional pond filter units, illumination means/lamps, air pumps, and/or feed automats. The control unit of the pond filter further controls the one or more auxiliary devices connected to the plugs, such as pumps, air pumps, automatic feeding devices based on input settings for each of the one or more auxiliary devices. The control unit further controls the cleaning cycle for cleaning of the filter in the vessel.

The filtering apparatus includes: a casing having an inlet for a fluid from the outside and an outlet for the fluid having filtered therein; filter elements having opposite-end openings, provided in the casing, and each filtering the fluid by allowing the fluid to flow therethrough in inside-to-outside directions; backwashing pipes sequentially connected to the opposite-end openings at different timings between the opposite-end openings of each filter element so as to backwash the filter element by allowing the fluid to flow therethrough in outside-in directions; removers each axially moved in the corresponding filter element by the filtration or backwashing flow, while sliding in contact with the inner periphery of the filter element so as to remove trapped objects; and a backwashing fluid drain pipe coupled to the discharge side of the backwashing pipes and allowing the trapped objects removed by each remover to be discharged to the outside.

This specification describes an intake filter for use, for example, in a system that collects greywater from baths or showers for re-use in toilet flushing. The intake filter provides essentially dead-end filtration. An influent by-pass may be provided, but the filter is cleaned as required to reduce use of the by-pass. Cleaning is performed when permeability of the filter declines. An upstream sensor may be used to detect the permeability of the filter. In one cleaning method, flowing water, optionally with air, is used to backwash the filter. The impulse of the flowing water also moves one or more valves to direct backwash water to a sanitary drain. For example, pumped effluent may impinge against a first flap to close an effluent drain, the first flap being mechanically linked to open a flap covering the sanitary drain.

An inline reductant filter assembly includes a filter housing, a filter media, and one or more valves. The filter housing is fluidly coupled to an upstream portion of a reductant line and a downstream portion of the reductant line. The filter media is positioned in the filter housing. The one or more valves are selectively movable from a first position to a second position. In the first position, the one or more valves permit fluid to flow along a first fluid flow path from the upstream portion of the reductant line, through the filter media, to the downstream portion of the reductant line. In the second position, the one or more valves prevent fluid from flowing along the first fluid flow path through the filter media.

A filtration system is disclosed, which comprises a filtration-element within a filtration chamber, and a valving device located exteriorly to the filtration chamber, for reversing the direction of fluid-flow through the filtration-element for backwashing. The valving device thus functions as a common valve for handling both filtration and backwash. The common valve is based on a linearly-movable plug located inside a valve housing which is communicable with the filtration chamber, with a source of fluid to be filtered, and with evacuation port for backwash fluid, through three respective openings in the valve housing, and is characterized by an uninterrupted bend-free flow-channel extending at least from exteriorly to an inlet opening of the valve housing, to the body of the filtration-element whenever the common valve is in a filtration mode of operation.

A filter device (10) includes a filter element (12) in a filter housing (14) with fluid connection points (16, 18) for the non-filtrate and filtrate. Fluid can be passed through the filter element in both directions for filtrating the non-filtrate or for backwashing for cleaning particle contaminations (72). A pressure control (36) generates a post-suctioning effect to improve the cleaning of the particle contaminations (72). The filter device (10) is designed as a one filter-element solution. In a predetermined exchange, the single filter element (12) for filtering can be used for backwashing or can be backwashed using the pressure control device (36). A hydraulic system (64) and a method for backwashing a filter element (12) of a filter device (10) is provided.