The present invention provides a new filter cleaning method that has cleaning performance superior to that of ultrasonic cleaning. The method for cleaning a filter of the present invention includes the steps of: generating a shock wave; and bringing the shock wave into contact with a filter to which a filler adhered, wherein in the shock wave contacting step, a pressure applied to the filter by the shock wave is 0.07 MPa or more.

The present invention provides a new filter cleaning method that has cleaning performance superior to that of ultrasonic cleaning. The method for cleaning a filter of the present invention includes the steps of: generating a shock wave; and bringing the shock wave into contact with a filter to which a filler adhered, wherein in the shock wave contacting step, a pressure applied to the filter by the shock wave is 0.07 MPa or more.

A portable pool filter cleaning assembly is configured to retain a pool filter on support rod and allow the pool filter to spin from a spray of water. The spinning filter releases debris from the filter surface through centrifugal force. The assembly has drainage features to ensure proper drainage of water collected within the interior of the pool filter and enable proper spinning from the spray of water. The assembly utilizes a support rod with a bottom filter retainer that is conical in shape for engaging with the pool filter aperture. The bottom filter retainer may further have a bearing that enables the pool filter to rotate freely about the rod with very little force. The assembly may include a stand for securing the support rod on a hard surface, such as concrete or on an uneven lawn surface.

A portable pool filter cleaning assembly is configured to retain a pool filter on support rod and allow the pool filter to spin from a spray of water. The spinning filter releases debris from the filter surface through centrifugal force. The assembly has drainage features to ensure proper drainage of water collected within the interior of the pool filter and enable proper spinning from the spray of water. The assembly utilizes a support rod with a bottom filter retainer that is conical in shape for engaging with the pool filter aperture. The bottom filter retainer may further have a bearing that enables the pool filter to rotate freely about the rod with very little force. The assembly may include a stand for securing the support rod on a hard surface, such as concrete or on an uneven lawn surface.

An apparatus and a method are provided for a heating, ventilation, and air conditioning (HVAC) system air filter for a building ventilation system. The HVAC system air filter comprises a supportive frame configured to orient the HVAC system air filter within the building ventilation system. A composite filter medium retained within the supportive frame comprises a cotton gauze portion and an electrostatic portion. The cotton gauze portion is configured for treatment with a filter oil composition to enhance airflow and filtration of air flowing through the composite filter medium. The electrostatic portion is configured to electrostatically attract and agglomerate airborne molecular contaminants and volatile organic compounds (VOCs) as small as 0.001 microns in diameter. In some embodiments, the composite filter medium comprises substances configured to release a fragrance into air passing through the composite filter medium.

An apparatus and a method are provided for a heating, ventilation, and air conditioning (HVAC) system air filter for a building ventilation system. The HVAC system air filter comprises a supportive frame configured to orient the HVAC system air filter within the building ventilation system. A composite filter medium retained within the supportive frame comprises a cotton gauze portion and an electrostatic portion. The cotton gauze portion is configured for treatment with a filter oil composition to enhance airflow and filtration of air flowing through the composite filter medium. The electrostatic portion is configured to electrostatically attract and agglomerate airborne molecular contaminants and volatile organic compounds (VOCs) as small as 0.001 microns in diameter. In some embodiments, the composite filter medium comprises substances configured to release a fragrance into air passing through the composite filter medium.

A method for cleaning at least one filter material, in particular a filter material used in the production of a respiratory protection mask (M), comprising the step of subjecting this filter material to a supercritical fluid, preferably supercritical CO.sub.2, with a density of less than 0.3 g/ml.

A cleaning device for cleaning a filter arrangement which has a first fluid connection, a second fluid connection, and a filter assembly between the first and second fluid connections and which has a surface to which contaminants can adhere. A generator device for generating a gas-fluid mixture includes a receiving chamber for receiving a fluid, and a pressurized gas generating device. A first pipe assembly is connected to the generator device so that the gas-fluid mixture can be provided under pressure into the filter arrangement. A second pipe assembly is connectable to the second fluid connection and a collection device. The collection device collects the gas-fluid mixture and contaminants entrained from the filter arrangement. The first pipe assembly has a deflection pipe section which allows the receiving chamber to be filled with fluid without fluid entering the filter arrangement before the gas-fluid mixture is generated.

A cleaning device for cleaning a filter arrangement which has a first fluid connection, a second fluid connection, and a filter assembly between the first and second fluid connections and which has a surface to which contaminants can adhere. A generator device for generating a gas-fluid mixture includes a receiving chamber for receiving a fluid, and a pressurized gas generating device. A first pipe assembly is connected to the generator device so that the gas-fluid mixture can be provided under pressure into the filter arrangement. A second pipe assembly is connectable to the second fluid connection and a collection device. The collection device collects the gas-fluid mixture and contaminants entrained from the filter arrangement. The first pipe assembly has a deflection pipe section which allows the receiving chamber to be filled with fluid without fluid entering the filter arrangement before the gas-fluid mixture is generated.

A method for recycling a scrapped polyvinylidene fluoride (PVDF) membrane through chemical cleaning-structural transformation-hydrophilicity is disclosed, which can extend the service life of scrapped PVDF membrane materials (namely, membrane at the end of service life). The method includes the following steps: cleaning a scrapped membrane with sodium hypochlorite and citric acid; treating the membrane with a structural transformation agent, where, irreversible contaminants are washed away while the PVDF membrane is subjected to pore expansion and hydrophilization; and with self-polymerization of dopamine on a membrane surface, further improving the hydrophilicity of the membrane surface, enhancing the anti-contamination performance, and repairing damaged points on the surface of the scrapped PVDF membrane produced during long-term operation.