# US 5,705,054 A · Filtering system

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- Number: US 5,705,054 A
- Document ID: US5705054A
- Status: Granted
- Kind: A
- Application number: 08/694,275
- Filed: 1996-08-08
- Granted: 1998-01-06
- Earliest claimed: 1996-08-08
- Assignees: Imatran Voima Oy
- Inventors: Timo Hyrsky
- Web page: https://patentgrep.com/patent/US5705054A

## CPC

- B01D 29/01: with flat filtering elements (B01D29/39 takes precedence)
- B01D 29/11: with bag, cage, hose, tube, sleeve or like filtering elements
- B01D 29/52: in parallel connection
- B01D 29/606: {by pressure measuring}
- B01D 29/66: by flushing, e.g. counter-current air-bumps
- B01D 2201/206: by the weight of the liquid in a tube, e.g. siphon, barometric leg
- 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)

## Abstract

A system for filtering liquids like cooling water and emergency cooling water in nuclear power stations and other industrial plants wherein a continuous circulation of a coolant or other liquid has to be secured. The system comprises a first filtering surface and a first filtrate space which is at least partially limited by the first filtering surface and at least one further filtering surface with a second filtrate space which is at least partially limited by a filtering surface. A filtrate outlet channel is connected to the first filtrate space and a siphon connects the filtrate spaces.

## Claims

### Claim 1

A filtering system for filtering liquids in plants where a continuous flow of liquid through the filtering system has to be secured, the system comprising:
a first filtering surface,
a first filtrate space which is at least partially limited by the first filtering surface,
at least one further filtering surface,
at least one further filtrate space which is at least partially limited by a filtering surface,
a filtrate outlet channel connected to the first filtrate space, and
at least one siphon connecting two of the filtrate spaces, the number of siphons being sufficient to connect the spaces pairwise so that each space is connected to at least an other space through a siphon.

### Claim 2 (depends on 1)

A system according to claim 1, comprising two filtering surfaces, two filtrate spaces and one siphon.

### Claim 3 (depends on 1)

A system according to claim 1, comprising three filtering surfaces, three filtrate spaces and two siphons.

### Claim 4 (depends on 1)

A system according to claim 1, comprising detector means for detecting the height of the liquid in a siphon.

### Claim 5 (depends on 1)

A system according to claim 1, wherein each filtering surface has different permeability to the filtered liquid.

### Claim 6 (depends on 1)

A system according to claim 1, comprising a gas inblow pipe connected to each siphon for blowing gas into the siphon.

### Claim 7 (depends on 1)

A system according to claim 1, comprising at least two siphons having different heights.

### Claim 8

A filtering system for filtering liquids in plants where a continuous flow of liquid through the filtering system has to be secured, the system comprising:
a first filtering surface,
a first filtrate space which is at least partially limited by the first filtering surface,
a second filtering surfaces having different permeability to the filtered liquid than the first surface,
second filtrate space which is at least partially limited by the second filtering surface,
a filtrate outlet channel connected to the first filtrate space, and
a siphon connecting the filtrate spaces.

### Claim 9

A filtering system for filtering liquids in plants where a continuous flow of liquid through the filtering system has to be secured, the system comprising:
a first filtering surface,
a first filtrate space which is at least partially limited by the first filtering surface,
at least two further filtering surfaces having different permeability to the filtered liquid,
at least two further filtrate spaces which are at least partially limited by a filtering surface,
a filtrate outlet channel connected to the first filtrate space, and
two siphons connecting the spaces pairwise so that each space is connected to at least an other space through a siphon.

### Claim 10 (depends on 8)

A system according to claim 8, comprising a gas inblow pipe connected to each siphon.

### Claim 11 (depends on 1)

A system wherein several filtering systems described in claim 1 are connected parallel to each other.

### Claim 12 (depends on 9)

A system according to claim 9, comprising a gas inblow pipe connected to each siphon.