A filtering unit (1) for aquariums of the hang on back type comprising: a housing (6); a suction pipe (2) provided with a lower inlet (3); and a pump (5) integral with said housing (6) and configured to determine a water circulation through a recirculation path extended inside the filtering unit (1) between said inlet (3) and said outlet mouth (4), wherein a non-return valve (10) is advantageously provided upstream of the pump (5) to maintain a water volume necessary for priming the pump (5) itself.

Disclosed herein is a waste oil purification apparatus that purifies waste lubricating oil and waste oil at high speed by a precipitation induction method in a vacuum state and further completely removes metallic foreign materials, thereby improving the efficiency of the purification of waste oil. The waste oil purification apparatus may include a purifier configured to purify waste oil such as waste lubricating oil or general waste oil by a filtering method, and a separator configured to separate and remove foreign materials contained in the waste oil purified by the purifier.

Disclosed herein is a waste oil purification apparatus that purifies waste lubricating oil and waste oil at high speed by a precipitation induction method in a vacuum state and further completely removes metallic foreign materials, thereby improving the efficiency of the purification of waste oil. The waste oil purification apparatus may include a purifier configured to purify waste oil such as waste lubricating oil or general waste oil by a filtering method, and a separator configured to separate and remove foreign materials contained in the waste oil purified by the purifier.

A separator, for separating solids from a liquid, comprises a hydrodynamic separator, a first filtration device, a first backwash device, a second filtration device, and a second backwash device. The first filtration device comprises a first inlet at a first level for receiving at least a first portion of the liquid from the hydrodynamic separator, and a first filter for filtering the first portion of the liquid received via the first inlet. During filtration of the first portion of the liquid, the first portion of the liquid passes through the first filter away from the first inlet and a first portion of solids is retained by the first filter. The first filter is located between the first inlet and the first backwash device. The first backwash device is configured to alternately prevent and allow the passage of the first portion of the liquid through the first backwash device such that, when the passage of the first portion of the liquid through the first backwash device is prevented, the first portion of the liquid that has passed through the first filter passes back through the first filter toward the first inlet so as to remove the first portion of solids from the first filter. The second filtration device comprises a second inlet at a second level higher than the first level for receiving a second portion of the liquid from the hydrodynamic separator, and a second filter for filtering the second portion of the liquid received via the second inlet. During filtration of the second portion of the liquid, the second portion of the liquid passes through the second filter away from the second inlet, and a second portion of solids is retained by the second filter. The second filter is located between the second inlet and the second backwash device. The second backwash device is configured to alternately prevent and allow the passage of the second portion of the liquid through the second backwash device such that, when the passage of the second portion of the liquid through the second backwash device is prevented, the second portion of the liquid that has passed through the second filter passes back through the second filter toward the second inlet so as to remove the second portion of solids from the second filter.

A separator, for separating solids from a liquid, comprises a hydrodynamic separator, a first filtration device, a first backwash device, a second filtration device, and a second backwash device. The first filtration device comprises a first inlet at a first level for receiving at least a first portion of the liquid from the hydrodynamic separator, and a first filter for filtering the first portion of the liquid received via the first inlet. During filtration of the first portion of the liquid, the first portion of the liquid passes through the first filter away from the first inlet and a first portion of solids is retained by the first filter. The first filter is located between the first inlet and the first backwash device. The first backwash device is configured to alternately prevent and allow the passage of the first portion of the liquid through the first backwash device such that, when the passage of the first portion of the liquid through the first backwash device is prevented, the first portion of the liquid that has passed through the first filter passes back through the first filter toward the first inlet so as to remove the first portion of solids from the first filter. The second filtration device comprises a second inlet at a second level higher than the first level for receiving a second portion of the liquid from the hydrodynamic separator, and a second filter for filtering the second portion of the liquid received via the second inlet. During filtration of the second portion of the liquid, the second portion of the liquid passes through the second filter away from the second inlet, and a second portion of solids is retained by the second filter. The second filter is located between the second inlet and the second backwash device. The second backwash device is configured to alternately prevent and allow the passage of the second portion of the liquid through the second backwash device such that, when the passage of the second portion of the liquid through the second backwash device is prevented, the second portion of the liquid that has passed through the second filter passes back through the second filter toward the second inlet so as to remove the second portion of solids from the second filter.

In one aspect, a modular filter assembly for filtering fluid that flows in a flow direction therethrough is disclosed. The assembly includes a first housing section having a first filter element; a second housing section having a second filter element; and a connector disposed between the first and second housing sections. A housing includes the first housing section, the connector, and the second housing section. The flow direction is through the first and second filter elements in series.

In one aspect, a modular filter assembly for filtering fluid that flows in a flow direction therethrough is disclosed. The assembly includes a first housing section having a first filter element; a second housing section having a second filter element; and a connector disposed between the first and second housing sections. A housing includes the first housing section, the connector, and the second housing section. The flow direction is through the first and second filter elements in series.

A water purifying apparatus includes a head that is configured to couple to a filter and defines a water inlet and a water outlet, and a shaft provided inside the head, rotatably mounted between the water inlet and the water outlet, and having a filtering passage configured to connect the water inlet to the water outlet so that water introduced into the water inlet is discharged to the water outlet via the filter. The shaft includes a shaft inlet and a shaft outlet, which are opened to respectively communicate with the water inlet and the water outlet so as to define the filtering passage, and a water inlet blocking portion and a water outlet blocking portion, which are provided between the shaft inlet and the shaft outlet to shield opened surfaces of the water inlet and the water outlet.

The present disclosure relates to a solenoid valve. The solenoid valve includes an armature provided inside the sleeve, a plunger configured to ascend and descend by the operation of the armature, an elastic member configured to press the plunger toward the armature, a magnet core having a through hole in which the plunger and the elastic member are provided and forming an inner space in a longitudinal direction, a valve seat provided in the inner space and on which an orifice penetrating in an axial direction is formed to be opened and closed by the plunger, and a plurality of flow resistance members each including a ring body interposed between the valve seat and the magnet core to generate a flow resistance of a braking fluid, and a slot formed at one side of the ring body to penetrate through the ring body so that the braking fluid passes therethrough.

The present disclosure relates to a solenoid valve. The solenoid valve includes an armature provided inside the sleeve, a plunger configured to ascend and descend by the operation of the armature, an elastic member configured to press the plunger toward the armature, a magnet core having a through hole in which the plunger and the elastic member are provided and forming an inner space in a longitudinal direction, a valve seat provided in the inner space and on which an orifice penetrating in an axial direction is formed to be opened and closed by the plunger, and a plurality of flow resistance members each including a ring body interposed between the valve seat and the magnet core to generate a flow resistance of a braking fluid, and a slot formed at one side of the ring body to penetrate through the ring body so that the braking fluid passes therethrough.