US 11,872,507 B2Granted

Filter candle and method for operating such filter candle

AssigneeBollfilter Nordic Aps

InventorsRobert Jellinggaard, Sigurd Ildvedsen

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Abstract

A filter candle (1) in a backflush filter housing (2) has a cylindrical filter wall (3) and includes an internal hollow flushing element (8) divided into a flushing section (9) having a flushing port (10) for backflushing and a turbine section (11) for rotation of the flushing element. The flushing section tapers from a first end to a second end. The turbine section tapers from a first end to a second end and has turbine blades arranged on the outside. The first end of the flushing section is connected to the first end of the turbine section at a transition position (21). An outside of the flushing element forms a cylindrical restriction at the transition position so that the part of the cylindrical filter wall of the filter candle extending at the turbine section may be backflushed by means of fluid also driving the turbine.

Claims20

Dependent claims

A filter candle for mounting in a backflush filter housing, the filter candle comprising:

a cylindrical filter wall which encloses an interior of the filter candle and which is formed by a filter medium through which fluid to be filtered may flow from the interior to an outside of the filter candle, the cylindrical filter wall having an inner diameter;
a first end and a second end of which at least one is open for fluid flow to the interior of the filter candle and a central axis extending between the first end and the second end;
a flushing element arranged in the interior of the filter candle and being rotatable about the central axis, the flushing element being divided into a flushing section provided with at least one flushing port for backflushing part of the cylindrical filter wall and a turbine section provided with a turbine for rotating the flushing element, the flushing section having a first end and a second end and being formed as a hollow shaft tapering from the first end to the second end, the at least one flushing port being provided in at least one flushing rib arranged on the hollow shaft and extending from the first to the second end of the flushing section, the turbine section having a first end and a second end and being formed as a hollow shaft tapering from the first end to the second end and the turbine being formed by turbine blades arranged on the outside of the hollow shaft of the turbine section, the first end of the flushing section being connected to the first end of the turbine section at a transition position, wherein
an outside of the flushing element forms a cylindrical restriction at the transition position for, during a backflushing operation, at least substantially restricting fluid flow from the flushing section to the turbine section between the cylindrical restriction and an inside of the cylindrical filter wall, and
the cylindrical restriction has an outer diameter being at least 85 percent of the inner diameter of the cylindrical filter wall.

2 more elements

A method for operating a filter candle arranged in a backflush filter housing, the filter candle having a cylindrical filter wall which encloses an interior of the filter candle and which is formed by a filter medium, the filter candle including a flushing element arranged in the interior of the filter candle and being rotatable about a central axis of the filter candle, the flushing element being divided into a flushing section provided with at least one flushing port for backflushing part of the cylindrical filter wall and a turbine section provided with a turbine for rotating the flushing element, the flushing section and the turbine section being connected at a transition position, the method comprising:

during normal operation of the filter candle, providing fluid to be filtered to flow through at least one end of the filter candle to the interior of the filter candle and through the filter medium to an outside of the filter candle;
during backflushing operation of the filter candle, causing already filtered fluid to flow from the outside of the filter candle, through at least part of the filter medium, through the at least one flushing port of the flushing section, through the interior of the flushing element, out through an end of the filter candle and out through a flushing outlet of the backflush filter housing;
and
during backflushing operation of the filter candle, driving the turbine by means of at least part of the fluid flowing to the flushing outlet, thereby rotating the flushing element, wherein
an outside of the flushing element forms a cylindrical restriction at the transition position, and
during backflushing operation, fluid flow from the flushing section to the turbine section of the flushing element is being restricted between the cylindrical restriction and an inside of the cylindrical filter wall to such an extent that the part of the cylindrical filter wall of the filter candle extending at the turbine section is being backflushed by means of fluid also driving the turbine.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/293,546Filed 13 Nov 2019
Priority: DK PA 2018 7074714 Nov 2018
Published: US 2022/0001310 A16 Jan 2022
Granted: 16 Jan 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B01D 29/17
Arranged for inward flow filtration: open-ended the arrival of the mixture to be filtered and the discharge of the concentrated mixture are…
B01D 29/682
With backwash arms, shoes or nozzles: with a rotary movement with respect to the filtering element
B01D 29/35
Self-supporting filtering elements: arranged for outward flow filtration
B01D 29/688
With backwash arms, shoes or nozzles: with backwash arms or shoes acting on the cake side