A dosing control method for micro-flocculation in ultrafiltration, including: calculating a preset value of a first differential pressure before an initial backwash and a preset value of a second differential pressure before a final backwash in each chemically enhanced backwash cycle; calculating a preset value of a third differential pressure between the first differential pressure and the second differential pressure according to the preset value of the first differential pressure and the preset value of the second differential pressure; obtaining a predicted value of the third differential pressure according to a differential pressure curve plotted based on online filtration differential pressure data; and comparing the preset value of the third differential pressure and the predicted value of the third differential pressure to determine whether to dose. A dosing control system is also provided.

A filtration system can comprise a pressure pump configured to apply a pressure on fluid flowing between a first chamber and a second chamber. The filtration system can also comprise a flow sensor configured to determine at least one parameter associated with fluid flowing across a membrane deposited between the first chamber and a second chamber. The filtration system can comprise a pressure sensor configured to determine pressure readings of the fluid flowing from the first chamber to the second chamber. The filtration system can comprise a filtration management system configured to cause the pressure pump to apply a constant pressure on fluid flowing across the membrane for a first predetermined time based on the pressure reading. The filtration management system can be configured to cause the pressure pump to reverse the fluid flow across the membrane.

A dosing control method for micro-flocculation in ultrafiltration, including: calculating a preset value of a first differential pressure before an initial backwash and a preset value of a second differential pressure before a final backwash in each chemically enhanced backwash cycle; calculating a preset value of a third differential pressure between the first differential pressure and the second differential pressure according to the preset value of the first differential pressure and the preset value of the second differential pressure; obtaining a predicted value of the third differential pressure according to a differential pressure curve plotted based on online filtration differential pressure data; and comparing the preset value of the third differential pressure and the predicted value of the third differential pressure to determine whether to dose. A dosing control system is also provided.

Method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions. In order for the method to purify wash water exiting from an exhaust gas scrubber sufficiently enough to be directly dischargeable to sea, and in order for a purification unit used to be small enough to be easily placed onboard a ship, exhaust gases are scrubbed in the exhaust gas scrubber and wash water containing impurities and exiting from the scrubber is supplied to the purification unit, circulated in an effluent circuit, and filtered through a semipermeable membrane of a filter to obtain purified effluent and a residue containing impurities, when necessary, the pH value of the purified effluent is adjusted to be at least 6.5, after which it is discharged into the sea or recycled to the scrubber while the residue containing impurities is led back to the effluent circuit.

Apparatus and method for semi-permeable membrane cleaning in particular, applying series of pulsed water stroke, made simultaneously with osmosis backward flow causing superposed membrane directional shaking and fouling detachment. Pulsed water stroke provided by water stroke generator as several momentum sharp changes in gauge pressure and induce velocity pulse of residual brine flow. The pulsed water strokes ideally induce resonance in the membrane. Osmosis backward wash may be provided either by injection for predetermined injection time, additional solution selected in such way that net driving pressure becomes opposite to normal osmotic operation thereby providing a backward flow of permeate towards to the side opposite to normal operation mode, so as to lift said foulant, or by throttling permeate exiting from the permeate enclosure, until the net driving pressure value become equal to zero, during application of precise synchronized and opposing brine and permeate pressure strokes thereby providing a plurality of quick RO-FO-RO process changes. These procedures allow a membrane to be kept continuously clean and operate at higher recovery.

Provided is a water purifier comprising: a filter unit filtering water supplied from a water source, including a reverse osmosis filter; a discharge unit discharging water filtered by the filter unit externally; a flushing portion connected to the reverse osmosis filter; and a controller configured to flow water filtered by the reverse osmosis filter to the flushing portion, and to flush the reverse osmosis filter.

A membrane filtration device includes a plurality of membrane separation units vertically disposed in multiple stages. The membrane separation unit has a primary side communicating with a backwash drainage system and a flushing-air supply system to receive supplied raw water and a secondary side communicating with a backwash-water supply system to collect permeate. The backwash-water supply system includes a backwash-water main pipe and a plurality of backwash-water branch pipes to feed the backwash water into the membrane separation units. The backwash drainage system includes a plurality of backwash-drainage branch pipes and a backwash-drainage main pipe connected in parallel to the backwash-drainage branch pipes. The flushing-air supply system includes an air main pipe for passing flushing air upward and a plurality of air branch pipes for feeding flushing air into the membrane separation units, the air branch pipes being connected in parallel to the air main pipe.

Systems and related methods for purging air burst supply piping of accumulated water prior to delivering pulses of pressurized air to an interior of a screen intake through the air burst supply piping. The systems and methods can include a purge compressor delivering a purging air supply at a head pressure slightly above a head pressure of water in the air burst supply piping, wherein the head pressure of the water is equivalent to a depth at which the intake screen. The system and methods can also include a purge line arranged in a parallel orientation to an air burst supply line, wherein both the purge line and the air burst supply line are operably coupled to a pressurized air tank.

According to one embodiment of the present invention, a control method for a water purifier comprises the steps of: filtering inflowing water so as to generate purified water; extracting the generated purified water; measuring the flow rate of the purified water extracted per unit time; flushing a filter part by using purified water generated in the filter part, when the extraction of the purified water is complete; and draining the flushed water to the outside through a residential water outlet of the filter part, wherein, in the purified water generation step, discharging of residential water generated in the purified water generation step is blocked according to the accumulated flow rate during a one-time extraction of the purified water, calculated on the basis of the flow rate of the purified water.

The present invention relates to a filtration device including: a flow rate control unit; a separation membrane module; a liquid flow rate detection unit detecting a liquid flow rate at a freely-selected part; and an external control unit controlling a state of the flow rate control unit, in which the external control unit includes: a target range setting step of setting a target flow rate range A; a control state recording step of recording a state S of the flow rate control unit when the liquid flow rate at the freely-selected part first enters within the target flow rate range A; a state setting step of setting the flow rate control unit to the state S; and a flow rate controlling step of controlling the liquid flow rate to be within the target flow rate range A.