# US 12,005,398 B2 · Method for filtering a liquid and filter device

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- Number: US 12,005,398 B2
- Document ID: US12005398B2
- Status: Granted
- Kind: B2
- Application number: 17/722,356
- Filed: 2022-04-17
- Published: 2022-08-25
- Granted: 2024-06-11
- Earliest claimed: 2019-10-28
- Assignees: Membion GmbH
- Applicants: Membion GmbH
- Inventors: Klaus Vossenkaul; Dirk Volmering
- Web page: https://patentgrep.com/patent/US12005398B2

## CPC

- B01D 63/02: Hollow fibre modules
- B01D 63/04: comprising multiple hollow fibre assemblies
- B01D 63/06: Tubular membrane modules
- B01D 65/02: Membrane cleaning or sterilisation {; Membrane regeneration}
- B01D 65/08: Prevention of membrane fouling or of concentration polarisation
- B01F 23/23112: {comprising the use of flow guiding elements adjacent or above the gas stream}
- B01F 23/237611: {Air}
- C02F 1/44: by dialysis, osmosis or reverse osmosis {(general membrane separation processes B01D61/00, membrane modules B01D63/00, electrodialysis C02F1/4693, combination of membrane modules and bioreactors C02F3/1268)}
- C02F 3/1278: {Provisions for mixing or aeration of the mixed liquor}
- B01D 2313/26: Specific gas distributors or gas intakes
- B01D 2315/06: Submerged-type; Immersion type
- B01D 2321/18: Use of gases
- B01D 2321/185: Aeration
- C02F 3/1273: {Submerged membrane bioreactors}
- C02F 3/208: {Membrane aeration (C02F3/201 takes precedence)}
- C02F 2203/006: details of construction, e.g. specially adapted seals, modules, connections
- C02F 2303/16: Regeneration of sorbents, filters
- Y02W 10/10: Biological treatment of water, waste water, or sewage
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01F: MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING (mixing paints B44D3/06)
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT

## Abstract

A method the filtering a liquid in a membrane filter immersed in the liquid and including membranes, the method including introducing a gas through a gas introduction device into a base of the membrane filter in successive pulses so that the membranes are cleaned wherein the gas introduction device includes a liquid flow channel which vertically penetrates a gas collection cavity and admits the liquid into a bottom of membrane filter; and initially filling a gas volume arranged below a free surface of the liquid and defined in a downward direction by an enclosed level of the liquid with the gas wherein the gas simultaneously displaces the liquid top down from a gas lifting channel until the enclosed level of the liquid drops below an inlet cross section of a gas flow out channel.

## Claims

### Claim 1

A method for filtering a liquid in a membrane filter immersed in the liquid and including membranes, the method comprising:
introducing a gas through a gas introduction device into a base of the membrane filter in successive pulses so that the membranes are cleaned wherein the gas introduction device includes a liquid flow channel which vertically penetrates a gas collection cavity and admits the liquid into a bottom of membrane filter; and initially
filling a gas volume arranged below a free surface of the liquid and defined in a downward direction by an enclosed level of the liquid with the gas wherein the gas simultaneously displaces the liquid top down from a gas lifting channel until the enclosed level of the liquid drops below an inlet cross section of a gas flow out channel; and subsequently
flowing the gas out of the gas volume downward through the gas lifting channel into a deflection portion connected at a bottom of the gas lifting channel and closed at a bottom side, from the channel with the deflection portion in an upward direction through the inlet cross section and through the gas flow out channel adjoining the inlet cross section at a top and flowing the gas to the free surface,
running a blocking flow of the liquid downward through a compensation inlet arranged below a gas lifting inlet to the inlet cross section, wherein the gas lifting inlet is arranged at a level of the inlet cross section or above; and
moving the blocking flow of the liquid along by the gas until the liquid fills the deflection portion and closes the inlet cross section for the gas,
wherein a continuous tubular upward open housing laterally envelops the membranes over an entire length of the membranes and is connected to the gas introduction device without gaps on top of the gas introduction device.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising:
after the level of the liquid in the deflection portion has dropped below the inlet cross section initially only flowing the gas through the gas flow out channel until the level of the liquid adjacent to the compensation inlet rises above the compensation inlet; and
only then running the blocking flow through the compensation inlet to the inlet cross section.

### Claim 3

A filter device, comprising:
a membrane filter for filtering a liquid, the membrane filter including membranes and a gas introduction device arranged below the membranes; and
a housing which laterally envelops the membranes over an entire length of the membranes and which is connected to the gas introduction device without gaps at a top of the gas introduction device,
the gas introduction device including
a liquid flow channel which vertically penetrates a gas collection cavity and admits the liquid into a bottom of the membrane filter, wherein the gas collection cavity is open at a base and defined by an upper wall and a lateral wall,
a gas inlet configured to flow a gas into the gas collection cavity,
a gas lifting channel where gas flows out of the gas collection cavity and empties the gas collection cavity, the gas lifting channel including a gas lifting inlet at a top in the gas collection cavity,
a deflection portion connected at a bottom of the gas lifting channel and closed at a bottom side, and
an inlet cross section arranged at a top of the deflection portion wherein a gas outflow channel is connected at a top of the inlet cross section.

### Claim 4 (depends on 3)

The filter device according to claim 3,
wherein a compensation inlet is arranged above and leading into a downwards extending compensation channel, and
wherein the compensation inlet is arranged below the gas lifting inlet and the downwards extending compensation channel is arranged open towards the inlet cross section.

### Claim 5 (depends on 4)

The filter device according to claim 4, wherein the compensation inlet is arranged at a level of the inlet cross section or above.

### Claim 6 (depends on 4)

The filter device according to claim 4, wherein the downwards extending compensation channel which connects to the compensation inlet in a direction towards the deflection portion.

### Claim 7 (depends on 6)

The filter device according to claim 6, wherein the downwards extending compensation channel leads into the gas lifting channel.

### Claim 8 (depends on 6)

The filter device according to claim 6, wherein the downwards extending compensation channel leads parallel to the gas lift channel into the deflection portion.

### Claim 9 (depends on 6)

The filter device according to claim 6, wherein a cross section of the compensation inlet is larger than a minimum cross section of the downwards extending compensation channel.

### Claim 10 (depends on 3)

The filter device according to claim 3, wherein the housing is a continuous tube.

### Claim 11 (depends on 3)

The filter device according to claim 3, further comprising a gas distributor arranged below the membranes, wherein the gas outflow channel leads into the gas distributor.

### Claim 12

A filter device, comprising:
a membrane filter for filtering a liquid, the membrane filter including membranes and a gas introduction device arranged below the membranes; and
a housing which laterally envelops the membranes over an entire length of the membranes and which is connected to the gas introduction device without gaps at a top of the gas introduction device,
the gas introduction device including
a liquid flow channel which vertically penetrates a gas collection cavity and admits the liquid into a bottom of the membrane filter, wherein the gas collection cavity is open at a base and defined by an upper wall and a lateral wall,
a gas inlet configured to flow a gas into the gas collection cavity,
a gas lifting channel including a gas lifting inlet at a top in the gas collection cavity,
a deflection portion connected at a bottom of the gas lifting channel and closed at a bottom side,
an inlet cross section arranged at a top of the deflection portion wherein a gas outflow channel is connected at a top of the inlet cross section, and
a compensation inlet arranged below the gas lifting inlet to the inlet cross section, wherein the gas lifting inlet is arranged at a level of the inlet cross section or above; and
wherein a blocking flow of the liquid downward runs through the compensation inlet, and
wherein moving the blocking flow of the liquid along by the gas until the liquid fills the channel with the deflection portion and closes the inlet cross section for the gas.

### Claim 13

A method for filtering a liquid in a membrane filter immersed in the liquid and including membranes, the method comprising:
introducing a gas through a gas introduction device into a base of the membrane filter in successive pulses so that the membranes are cleaned wherein the gas introduction device includes a liquid flow channel which vertically penetrates a gas collection cavity and admits the liquid into a bottom of membrane filter; and initially
filling a gas volume arranged below a free surface of the liquid and defined in a downward direction by an enclosed level of the liquid with the gas wherein the gas simultaneously displaces the liquid top down from a gas lifting channel until the enclosed level of the liquid drops below an inlet cross section of a gas flow out channel; and subsequently
flowing the gas out of the gas volume downward through the gas lifting channel into a deflection portion connected at a bottom of the gas lifting channel and closed at a bottom side, from the deflection portion in an upward direction through the inlet cross section and through the gas flow out channel adjoining the inlet cross section at a top and flowing the gas to the free surface,
wherein a continuous tubular upward open housing laterally envelops the membranes over an entire length of the membranes and is connected to the gas introduction device without gaps on top of the gas introduction device.