GB2631237A

GB2631237A - Fluid treatment apparatus

Info

Publication number: GB2631237A
Application number: GB2309326.3A
Authority: GB
Inventors: Martin Mulligan Sean; George Leonard Peter; Fionn Mannion Paul; Michael Clifford Fergus
Original assignee: Vortech Water Solutions Ltd
Current assignee: Vortech Water Solutions Ltd
Priority date: 2023-06-21
Filing date: 2023-06-21
Publication date: 2025-01-01
Also published as: WO2024261246A1

Abstract

An apparatus 100 comprises a housing 102, defining a first flow path 104. The flow path comprises an inlet port 106 in communication with a first fluid source 200, a second inlet 108 in communication with a second fluid 300, and a fluid outlet 110 whereby fluid is returned to the first source 200. A second fluid inlet 108 is located between the inlet 106 and the outlet 110. The apparatus further comprises a filter module 400 comprising an inlet port 406 in communication with the flow path 104, a filtrate outlet 408 in communication with a filtrate receiving apparatus 500, and a concentrate outlet 410 which returns fluid to the first source 200. A filter unit 412 defines a section of the filter module flow path 404 and divides the filter module flow path 404 into filtrate 416 and concentrate 418 flow paths.

Description

FLUID TREATMENT APPARATUS

The present disclosure relates to a fluid treatment apparatus.

In particular the disclosure is concerned with a fluid treatment apparatus for filtering a fluid, and a fluid treatment system comprising a fluid treatment apparatus.

Background

Membrane filtration systems are becoming popular in wastewater treatment plants due to their ability to produce high quality filtrate. In such systems the membranes are submerged in tanks of fluids to be filtered, with the fluid being filtered as it passes through the membrane.

Conventionally the tank is dedicated to the filtration step of the wastewater treatment with other processes (such as aeration) often happening in other tanks in series with the filtration tank, which adds to the size of the treatment plant. The extra size is problematic as it reduces the number of treatment plant units that can be installed in a given space and/or competes for space with other equipment necessary to a facility it forms part of.

Membrane clogging and fouling is a common problem. Fouling is also a significant challenge in applications where diffuser membranes foul regularly, for example in applications where solids concentrations are higher. One solution to this problem is to scour the membrane to remove the debris so fluid can continue to pass through the membrane effectively. This may be achieved with coarse bubble diffusers provided at the base of and/or under the membranes.

These release bubbles which scour the membrane interface of solids. While effective, generation of the bubbles requires high energy usage. Even with scouring, the membranes (which are costly) need to be replaced regularly. Additionally, the outlets for the bubble diffusers (which must be located at the bottom of the fluid tank so the bubbles can travel along the membrane) also become clogged and fouled, which result in them needing frequent cleaning and/or replacement to maintain the efficiency of the filtration system.

Replacement of the membranes and/or cleaning or replacement of the bubble diffuser outlets requires the filtration system to be shut down and drained. Not only is it inconvenient for the system to be non operational for an extended period of time while this is done, but the fluid removed from the tank (which is by its very nature a pollutant) needs to be handled and processed correctly.

Hence a fluid treatment apparatus with a filtering system which is easier and quicker to maintain, and enables a system which is more compact and efficient than examples of the related art, is highly desirable. -2 -

Summary

According to the present disclosure there is provided an apparatus and system as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

Accordingly, there may be provided a fluid treatment apparatus (100). The fluid treatment apparatus (100) may comprise a housing (102) which defines a first flow path (104). The housing (102) may comprise: a first fluid inlet port (106) for fluid communication with a first fluid source (200); a second fluid inlet port (108) for fluid communication with a second fluid source (300) and a fluid outlet port (110) for fluid delivery to the first fluid source (200). The second fluid inlet port (108) may be located along the first flow path (104) between the first fluid inlet port (106) and the fluid outlet port (110).

The fluid treatment apparatus (100) may further comprise a filter module unit (400). The filter module unit (400) may comprise: a filter module flow inlet port (406), the filter module flow inlet port (406) being in fluid communication with the first flow path (104); a filtrate outlet port (408) for fluid communication with a filtrate receiving apparatus (500) and a concentrate outlet port (410) for fluid communication with the first fluid source (200).

The filter module unit (400) may define a filter module flow path (404) which extends from the filter module flow inlet port (406) to the filtrate outlet port (408) and the concentrate outlet port (410).

The filter module unit (400) may comprise a filter unit (412) which defines a section of the filter module flow path (404) and divides the filter module flow path (404) into a filtrate flow path (416) and a concentrate flow path (418).

The filter module filtrate flow path (416) may extend from the filter unit (412) to the filtrate outlet port (408). The filter module concentrate flow path (418) may extend from the filter unit (412) to the concentrate outlet port (410).

The fluid treatment apparatus (100) may further comprise a filter module flow path offtake port (112) located along the first flow path (104) between the first fluid inlet port (106) and the second fluid inlet port (108). The filter module flow inlet port (406) may be in fluid communication with the first flow path (104) via the filter module flow path offtake port (112).

A debris removal feature (140) may be provided upstream of the filter module flow path offtake port (112), configured to alter the fluid flow around the filter module flow path offtake port (112) to thereby bias debris flow along the first flow path (104) rather than the filter module flow path (404).

The filter module flow path offtake port (112) may be provided with a pre-filter (428) upstream of and in series with the filter module flow path (404). -3 -

The fluid treatment apparatus (100) may further comprise a fluid pump (600) configured for fluid communication with the first fluid source (200) and the first fluid inlet port (106) to thereby deliver pressurised first fluid (202) to the first flow path (104).

The filter module unit (400) may comprise a filtrate flow control valve (420) provided in the filter module filtrate flow path (416).

The filtrate outlet port (408) may be provided along the filter module flow path (404) between the filter module flow inlet port (406) and the concentrate outlet port (410).

The filter module unit (400) may comprise a concentrate flow control valve (426) provided in the filter module concentrate flow path (418).

The filter module unit (400) may comprise a filtrate flow pressure sensor (422) provided in the filter module filtrate flow path (416).

The filter module filtrate flow path (416) may be in flow communication with a vacuum pump (610) configured and operable to draw filtrate along the filtrate flow path (416) to the filtrate outlet port (408).

The fluid treatment apparatus (100) may further comprise a vortex generator apparatus (800). The vortex generator apparatus (800) may comprise a fluid tank (802) defined by a sidewall (804), a first fluid intake duct (806) in fluid communication with the first fluid inlet port (106), and the first fluid intake duct (806) extending to a curved flow channel (808) defined between a first sidewall segment (810) of the fluid tank sidewall (804) and a second sidewall segment (812) of the fluid tank sidewall (804). The first fluid intake duct (806) may be provided substantially on a tangent to the first sidewall segment (810) of the fluid tank (802) sidewall (804) and aligned to deliver the first fluid (202) to an internal surface (814) of the first sidewall segment (810).

The first fluid intake duct (806) may be interfaced with an outer surface (816) of the fluid tank (802) to communicate the first fluid (202) along the outer surface (816).

The filter module flow inlet port (406) may be provided along the first flow path (104) in the first fluid intake duct (806), the curved flow channel (808) and/or the fluid tank (802).

The filter module flow inlet port (406) may be provided along the first flow path (104) between the first fluid inlet port (106) and the first fluid intake duct (806).

The filter module concentrate outlet port (410) may be provided along the first flow path (104) in the first fluid intake duct (806), the curved flow channel (808) and/or the fluid tank (802).

The filter module concentrate outlet port (410) may be provided proximate to the second fluid inlet port (108). -4 -

The filter module concentrate outlet port (410) may be provided along the first flow path (104) between the first fluid inlet port (106) and the first fluid intake duct (806).

The filter module flow path (404) may bypass the first flow path (104) downstream of the filter module flow inlet port (406) such that the filter module flow path (404) is configured to deliver concentrate directly to the first fluid source (200).

The filter module unit (400) may be supported by the first fluid intake duct (806) and/or the fluid tank (802).

The filter module flow path (404) may comprise a spiral section (430) with the filter module flow inlet port (406) spaced apart from the concentrate outlet port (410) by the spiral section (430).

The spiral section (430) may extend in a plane, decreasing in radius from filter module flow inlet port (406) to the concentrate outlet port (410).

The fluid treatment apparatus (100) may comprise at least two filter module units (400) provided in parallel and side-by-side and/or with one stacked on top of another.

The fluid outlet port (110) may be defined by the fluid tank (802).

The fluid treatment apparatus (100) may further comprise a fluid outlet duct (820) arranged in flow communication with the fluid outlet port (110) and terminating in a duct exit (822).

The fluid outlet duct (820) may comprise a divergent section (824) such that the fluid outlet duct exit (822) has an internal cross-sectional area which is larger than the internal cross-sectional area of the fluid outlet port (110).

The second fluid inlet port (108), the fluid outlet port (110) and the duct exit (822) may be provided in series along a common axis (826).

The sidewall (804) of the fluid tank (802) may define a spiral centred on the fluid outlet port (110).

The filter module unit (400) may be provided outside of the housing (102) such that the filter module unit (400) is spaced apart from the first flow path (104) by the housing (102).

The filter module unit (400) may be provided in the first flow path (104).

The first fluid intake duct (806) may comprise a divergent section (830).

A second fluid flow control valve (460) may be provided in fluid communication with the second fluid inlet port (108) and is operable to control the flowrate through the second fluid inlet port (108).

The fluid treatment apparatus (100) may further comprise a fluid release line (160) in fluid communication with the first flow path (104) between the first fluid inlet port (106) and the second fluid inlet port (108). -5 -

There may be provided a fluid treatment system (900) comprising a fluid treatment apparatus (100) according to the present disclosure and a first fluid reservoir (902) of the first fluid (202), wherein the first fluid inlet port (106) and the fluid outlet port (110) of the fluid treatment apparatus (100) are in fluid communication with the first fluid (202) in the first fluid reservoir (902).

The fluid treatment system (900) may further comprise a first fluid level sensor (904, 906) configured to detect the level of the first fluid (202) in the first fluid reservoir (902) and generate a signal (924, 926) indicative of the level of the first fluid (202) in the first fluid reservoir (902). The control system (700) may be operable to receive the signal (924, 926) indicative of the level of the first fluid (202) in the first fluid reservoir (902) and, in dependence on the signal (924, 926) indicative of the level of the first fluid (202) in the first fluid reservoir (902), control the filtrate flow control valve (420) to regulate flow rate of filtrate in the filter module filtrate flow path (416).

The fluid treatment system (900) may be configured such that if the level of the first fluid (202) in the first fluid reservoir (902) is below a first predetermined value then the control system (700) is operable to control the filtrate flow control valve (420) such to reduce and/or stop the filtrate flow rate along the filter module filtrate flow path (416).

The fluid outlet duct exit (822) may be submerged in the first fluid (202).

Hence there is provided a fluid treatment apparatus with a filtering system which is easier and quickerto maintain, and enables a system which is more compact and efficientthan examples of the related art.

Brief Description of the Drawings

Examples of the present disclosure will now be described with reference to the accompanying drawings, in which: Figure 1 shows a plan (top) view of first example of a fluid treatment apparatus according

to the present disclosure;

Figure 2 is a side view of the fluid treatment apparatus shown in figure 1; Figure 3 shows a section of a filter module of the fluid treatment apparatus according to the present disclosure; Figure 4 shows a section of a fluid treatment system according to the present disclosure which includes a fluid treatment apparatus according to the present disclosure; Figure 5 shows an enlarged sectional view of a part of the first example of the fluid treatment apparatus; Figure 6 shows a side view of a second example of a fluid treatment apparatus according to the present disclosure; -6 -Figure 7 shows a plan (top) view of third example of a fluid treatment apparatus according to the present disclosure; Figure 8 is a side view of the fluid treatment apparatus shown in figure 7; Figure 9 shows a plan (top) view of a fourth example of a fluid treatment apparatus

according to the present disclosure;

Figure 10 is a side view of the fluid treatment apparatus shown in figure 9; Figure 11 shows a plan (top) view of a fifth example of a fluid treatment apparatus according to the present disclosure; Figure 12 is a side view of the fluid treatment apparatus shown in figure 11; Figure 13 shows a side view of a sixth example of a fluid treatment apparatus according to

the present disclosure; and

Figure 14 shows a sectional view of a part of examples of the fluid treatment apparatus.

Detailed Description

The present disclosure relates to a fluid treatment apparatus 100. The present disclosure also relates to a fluid treatment system 900 comprising a fluid treatment apparatus 100.

The apparatus and system of the present disclosure may be applicable to municipal wastewater treatment facilities, industrial wastewater treatment facilities, municipal and industrial activated sludge facilities such as membrane bioreactors (MBRs) and oxidation ditches, amongst 20 others.

The present disclosure relates to different examples of the fluid treatment apparatus 100. Features common to the different examples will are identified using the same reference numeral. Several examples of the fluid treatment apparatus are illustrated. Although there is some difference in configuration between the examples (for example the location and coupling of a filter module unit 400) all examples operate in a similar way.

As shown in the figures, the fluid treatment apparatus 100 comprises a housing 102. The housing 102 defines a first flow path 104. Figure 4 illustrates the direction of fluid flow as defined by the first flow path 104.

The housing 102 comprises a first fluid inlet port 106 for fluid communication with a first fluid source 200. That is to say, the first fluid inlet port 106 is configured for receiving the first fluid 202 from the first fluid source 200. The housing 102 also comprises a second fluid inlet port 108 for fluid communication with a second fluid source 300. That is to say, the second fluid inlet port 108 is configured for receiving the second fluid 302 from the second fluid source 300. The housing 102 also comprises (e.g. defines) a fluid outlet port 110 for fluid delivery to the first fluid -7 -source 200. The second fluid inlet port 108 is located along the first flow path 104 between the first fluid inlet port 106 and the fluid outlet port 110.

The first fluid source 200 may be a source of liquid such as, for example, a source of saline or wastewater. The fluid treatment system 900 comprises a second fluid source 300, which, by way of example, may be the ambient atmosphere, and the second fluid inlet port 108 is provided in fluid communication with the second fluid source 300.

As will be described, and as shown in figure 4, the fluid outlet port 110 is operable to deliver a combination of the second fluid 302 and concentrate extracted from the first fluid 202 back to the first fluid source 200. That is to say, the second fluid 302 and at least part of the constituents of the first fluid 202 are discharged from the fluid outlet port 110 together (i.e. at the same time). For example, the first fluid 200 may comprise wastewater which contains impurities, and the second fluid 300 may be air, and hence the fluid outlet port 110 is operable to deliver a combination of the second fluid 302 and impurities from the first fluid 202 to the first fluid source 200. Hence the first fluid source 200 may in fact contain the second fluid 302, while also being a source of the first fluid 202.

The fluid treatment apparatus 100 may also comprise a filter module flow path offtake port 112 located along the first flow path 104 between the first fluid inlet port 106 and the second fluid inlet port 108. That is to say, the fluid treatment apparatus 100 may also comprise a filter module flow path offtake port 112 provided in (e.g. defined by) the housing 102 along the first flow path 104 between the first fluid inlet port 106 and the second fluid inlet port 108.

The fluid treatment apparatus 100 also comprises a filter module unit 400. The filter module unit 400 comprises a filter module flow inlet port 406. The filter module flow inlet port 406 is in fluid communication with the first flow path 104 via the filter module flow path offtake port 112.

In the examples shown in the figures, the filter module unit 400 is provided outside of the housing 102. That is to say, in the examples shown in the figures, the filter module unit 400 is provided in a region offset from the first flow path 104. Put another way, examples shown, the filter module unit 400 is provided in a region spaced apart from the first flow path 104 (and hence also spaced apart from the first fluid 202) by the housing 102.

In other examples (not shown) the filter module unit 400 is provided in the first flow path 104. That is to say, in such examples, the filter module unit 400 is provided internal to the housing 102 such that as well as the first fluid 202 flowing into the filter module unit 400 through the filter module flow inlet port 406, the first fluid will also pass over the external surface of the filter module unit 400.

In each of the examples shown, the filter module unit 400 comprises a filtrate outlet port 408 for fluid communication with a filtrate receiving apparatus 500. The filtrate receiving -8 -apparatus 500 may be fluidly isolated from the first fluid source 200 and/or the second fluid source 300. The filtrate receiving apparatus 500 may include one or more of further filtrate purification equipment, equipment which utilises the filtrate and/or a reservoir for storage and/or transport of the filtrate.

In each of the examples shown, the filter module unit 400 also comprises a concentrate outlet port 410 for fluid communication with the first fluid source 200. That is to say, the concentrate outlet port 410 is directly and/or indirectly in fluid communication with the first fluid source 200. Put another way, the concentrate outlet port 410 is configured for delivery of concentrate to the first fluid source 200. That is to say, the concentrate outlet port 410 is provided in series between the filter module flow inlet port 406 and the first fluid source 200, and hence any concentrate leaving the filter module unit 400 passes the concentrate outlet port 410 before being returned to the first fluid source 200.

In operation, the filter module flow inlet port 406 is in fluid communication with a region of the first flow path 104 which is at a higher pressure than the filtrate outlet port 408 and/or the concentrate outlet port 410. The filter module flow inlet port 406 is upstream of the filtrate outlet port 408 and/or the concentrate outlet port 410 in the first flow path 104.

As will be described in more detail, the concentrate outlet port 410 may be directly or indirectly 410 in fluid communication with the first flow path 104. For example (and as shown in figure 1 to 6) the concentrate outlet port 410 may be in fluid communication with the first flow path 104 proximate to the second fluid inlet port 108. In other examples (not shown) the concentrate outlet port 410 may be in fluid communication with the supply to the second fluid inlet port 108 such that the concentrate and second fluid 302 exit the second fluid inlet port 108 together.

As illustrated in figures 3, 4, the filter module unit 400 defines a filter module flow path 404 which extends from the filter module flow inlet port 406 to the filtrate outlet port 408 and the concentrate outlet port 410. The filter module unit 400 may comprise a filter unit 412. The filter unit 412 may comprise a filter 414.

The filter 414 may be provided as a membrane module, for example a single tubular system, or multiple tubular system. Tubular membrane systems offer a significant flux rate. The internal membrane may be of a conventional configuration using standard membrane types such as tubular, spiral-wound or hollow fibre membrane element construction.

As illustrated in figure 3, the filter unit 412 defines a section of the filter module flow path 404 and divides the filter module flow path 404 into a filtrate flow path 416 and a concentrate flow path 418. The filter module filtrate flow path 416 extends from the filter unit 412 to the filtrate outlet port 408. The filter module concentrate flow path 418 extends from the filter unit 412 to the concentrate outlet port 410. -9 -

An example of the fluid treatment system 900 is illustrated in figure 4. The fluid treatment system 900 comprises the fluid treatment apparatus 100 and a first fluid reservoir 902. Hence, in this example, the first fluid reservoir 902 contains the first fluid 202 to provide the first fluid source 200. The first fluid inlet port 106 and the fluid outlet port 110 of the fluid treatment apparatus 100 are in fluid communication with the first fluid 202 in the first fluid reservoir 902. The fluid treatment system 900 thus comprises the fluid treatment apparatus 100 which circulates the first fluid 202 (and in some examples, where the second fluid 302 is air, aerates the first fluid 202 with the second fluid 302) as well as filtering the first fluid 202 to produce filtrate which is removed from the fluid reservoir 902 and deliver concentrate back to the fluid reservoir 902. Hence, in contrast to examples of the related art, the mixing (and, as applicable aeration) and filtering occur in the same (e.g. a single) fluid reservoir compartment using a single fluid treatment apparatus and using flow from common source (e.g. the pump 600). That is to say, the apparatus and system of the present disclosure is advantageous as mixing (and, as applicable aeration) and filtering is achieved at the same time, as part of the same process, by the same equipment unit.

The fluid treatment apparatus 100 may further comprise a fluid pump 600 configured for fluid communication with the first fluid source 200 and the first fluid inlet port 106 to thereby deliver pressurised first fluid 202 to the first flow path 104. An example location of the fluid pump 600 is shown in figures 1, 2 in broken/dashed lines indicating the fluid pump 600 may be provided in the duct which defines the first flow path 104. As illustrated in figures 1, 2 the fluid pump 600 may define the first fluid inlet port 106. The fluid inlet to the fluid pump 600 may define the first fluid inlet port 106. In an alternative example, the fluid pump 600 may be in fluid communication with the first fluid source 200 via the first flow path 104. The fluid pump 600 is in fluid communication with the first fluid source 200 to extract fluid from the first fluid source 200.

The fluid pump 600 may be operable to adjust the flowrate of the first fluid 202 through the first fluid inlet port 106.

The fluid pump 600 may be provided as an axial or mixed flow pump. The fluid pump 600 may also be provided as a centrifugal pump or an ultra-low-head horizontal pump. The fluid pump 600 may utilise a variable speed drive for adjusting the flowrate.

The fluid treatment apparatus 100 may comprise a control system 700 operable to control the fluid pump 600 to adjust the flowrate and/or pressure of the first fluid 202 through the first fluid inlet port 106.

As illustrated in figure 4, the filter module unit 400 may comprise a filtrate flow control valve 420 provided in the filter module filtrate flow path 416. The control system 700 may be operable to control the filtrate flow control valve 420 to regulate flow pressure in the filter module filtrate flow path 416 and thus the filtrate flow rate along the filter module filtrate flow path 416.

As illustrated in figures 1 to 4, the filtrate outlet port 408 may be provided along the filter module flow path 404 between the filter module flow inlet port 406 and the concentrate outlet port 410.

As illustrated in figure 2, the filter module unit 400 may comprise a concentrate flow control valve 426 provided in the filter module concentrate flow path 418. The control system 700 may be operable to control the concentrate flow control valve 426 to regulate flow pressure in the filter module concentrate flow path 418 and thus control increase and decrease pressure in the filter module concentrate flow path 418 and thus control increase and decrease the filtrate flow rate along the filter module filtrate flow path 416.

As illustrated in figure 4, the filter module unit 400 may comprise a filtrate flow pressure sensor 422 provided in the filter module filtrate flow path 416. The filtrate flow pressure sensor 422 may be operable to generate a signal 424 indicative of the fluid pressure in the filter module filtrate flow path 416, and the control system 700 may be operable to receive the filter module filtrate flow path signal 424 and, in dependence on the received filter module filtrate flow path signal 424, determine if the flow filter module flow path 404 is fouled/blocked.

As shown in the example of figure 4, the filter module filtrate flow path 416 may be in flow communication with a vacuum pump 610 configured and operable to draw filtrate along the filtrate flow path 416 to the filtrate outlet port 408.

As illustrated in figure 5, which shows an internal view of the housing 102 in a region where it is coupled to the filter module unit 400, a debris removal feature 140 may be provided upstream of the filter module flow path offtake port 112, configured to alter the fluid flow around the filter module flow path offtake port 112 to thereby bias debris flow along the first flow path 104 rather than along the filter module flow path 404. The debris removal feature 140 may be provided as bluff body configured as a turbulence generator. Hence the debris removal feature 140 is configured to generate turbulence as a self-cleaning mechanism in the region of the filter module flow path offtake port 112 Also as illustrated in figure 5, the filter module flow path offtake port 112 may be provided with a pre-filter 428 upstream of and in series with the filter module flow path 404.

The fluid treatment apparatus 100 may further comprise a vortex generator apparatus 800, a plan sectional view of this being shown in figure 14.

The vortex generator apparatus 800 is operational to mix fluids utilising a vortex generated by the vortex generator apparatus 800. In one example of the vortex generator apparatus 800 the vortex is generated and the fluids mixed despite the absence of an impeller in the vortex generator apparatus 800. That is to say, in such an examples, the vortex generator apparatus 800 according to the present disclosure is "impeller-free". An impeller, which is a rotor arranged to act on fluid or such that fluid acts on the rotor, is used in certain conventional vortex generators to generate a vortex or recover energy and to mix fluids.

In such an "impeller-free" example, the vortex generator apparatus 800 defines at least part of the first flow path 104. As shown in the figure the vortex generator 800 may comprise a fluid tank 802 defined by a sidewall 804.

The sidewall 804 may form at least part of the housing 102. That is to say, the housing 102 may comprise the sidewall 804. The second fluid inlet port 108 may be defined by the fluid tank 802. That is to say, the second fluid inlet port 108 may be provided in a wall of the fluid tank 802 so that the second fluid 302 can enter the fluid tank 802 through the second fluid inlet port 108. The fluid outlet port 110 may be defined by the fluid tank 802. That is to say, the fluid outlet port 110 may be provided in a wall of the fluid tank 802 so that fluid can be discharges from the fluid tank 108 through the fluid outlet port 110.

The fluid tank 802 (or housing 102) defines a vortex chamber 840 arranged to separately receive the first fluid 202 and the second fluid 302 (where, for example, the first fluid 202 and the second fluid 302 are different fluids) and arranged to discharge said fluids together. The vortex chamber 840 of the fluid tank 802 defines part of the first flow path 104. In an example in which the vortex generator 800 is "impellor free" the flow path through the vortex chamber 840 may be a static flow path which differs from the flow path in a conventional vortex generator, where an impeller displaces fluid or fluid displaces the impeller, and so causes the flow path to change dynamically. That is to say, the flow path through the tank of an "impellor free" vortex generator 800 is defined by static (e.g. non rotatable) features (e.g. walls) which are fixed relative one another. Hence the flow path through the tank of an "impellor free" vortex generator 800 may thus be defined only by static (e.g. non rotatable) features (e.g. walls) which are fixed relative one another.

The fluid tank 802 is arranged to receive the first fluid 202 through the first fluid inlet port 106 and, separately, the second fluid 302 through the second fluid inlet port 108, and to discharge said fluids through the fluid outlet port 110. The fluid tank 802 further comprises at least one sidewall 804 which defines the vortex chamber 840. The side wall has an inner/internal surface 814. Hence the internal surface 814 of the sidewall 804 bounds/defines the vortex chamber 840 (or "enclosed volume") defined by the fluid tank 802.

As shown in the figures, a first fluid intake duct 806 may be in fluid communication with the first fluid inlet port 106. The first fluid intake duct 806 may comprise a divergent section 830 along its length. Hence the internal cross-section of the first fluid intake duct 806 may increase towards the fluid tank 802.

The fluid intake duct 806 may comprise a plurality of sections in series or be formed integrally. As illustrated in figure 14, the first fluid intake duct 806 is arranged to discharge fluid into the fluid tank 802. More particularly, the first fluid intake duct 806 is arranged to engage the fluid tank 802 tangentially to the curvature of the sidewall 804 and terminates at the curved flow channel 808.

The first fluid intake duct 806 may define the first fluid inlet port 106. As shown in the figures, there may be provided a pump duct 818 upstream of, and in fluid communication with, the first fluid intake duct 806. The first fluid intake duct 806 may be in fluid communication with the first fluid inlet port 106 either directly, or indirectly via a further duct, for example the pump duct 818.

The pump duct 818 may define the first fluid inlet port 106 and extend from the first fluid inlet port 106 to the fluid intake duct 806. The fluid pump 600 may be provided in the pump duct 818 between the first fluid inlet port 106 to the fluid intake duct 806. The fluid pump 600 may be provided at and/or define the fluid inlet port 106.

Figure 14 is a partial cutaway view of an example of a vortex generator apparatus 800. As illustrated in figure 14, the first fluid intake duct 806 may extend to a curved flow channel 808 defined between a first sidewall segment 810 of the fluid tank sidewall 804 and a second sidewall segment 812 of the fluid tank sidewall 804. Put another way, the curved flow channel 808 may be bounded by the first sidewall segment 810 and the second sidewall segment 812 such that flow through the flow channel 808 is contained therein. That is to say, the first fluid intake duct 806 may be provided between the first fluid inlet port 106 and the curved flow channel 808 along the first flow path 104. The first fluid intake duct 806 may be provided substantially on a tangent to the first sidewall segment 810 of the fluid tank sidewall 804 and aligned to deliver the first fluid 202 to an internal surface 814 of the first sidewall segment 810.

With respect to the generally cylindrical geometry of the fluid tank 802, the first sidewall segment 810 may be a radially outer sidewall segment, while the second sidewall segment 812 may be a radially inner sidewall segment. That is to say, the first sidewall segment 810 may be radially outward of the second sidewall segment 812. Accordingly, flow through the flow channel 808 may be radially confined. Hence the flow channel 808 may be configured to direct flow in a circumferential direction around the inner surface 814 of the sidewall 804.

As shown in figure 14, the first fluid intake duct 806 may be interfaced with an outer surface 816 of the fluid tank 802 to communicate the first fluid along the outer surface 816. Put another way, the second sidewall segment 812 may extend from a portion of the side wall 804 which forms an interface with the first fluid intake duct 806, so that the outer surface 816 of the sidewall 804 extends to provide a flow surface of the flow channel 808.

The fluid tank 802 is arranged generally symmetrical about a fluid rotational axis 826 about which the vortex is formed. In particular, the sidewall 804 is arranged to define a logarithmic spiral centred on the fluid rotational axis 826.

The fluid intake duct 806 is provided substantially on a tangent to the sidewall 804 of the fluid tank 802 and aligned to deliver a first fluid to the internal surface 814 of the sidewall 804.

The described arrangement causes a fluid injected through the first fluid inlet port 106 to swirl in the fluid tank 802, causing the formation of a vortex therein through the principles of circulation. The length of the sidewall 804 is such that the sidewall extends around the fluid rotational axis 826 for at least one full revolution. In other words, the arc-length of the sidewall 804 is such that the sidewall achieves at least one rotation.

The sidewall 804 of the fluid tank 802 extends along the fluid rotational axis 826, and extends around the fluid rotational axis 826. More particularly, the sidewall 804 extends along the fluid rotational axis 826 for a length corresponding to the depth of the fluid tank 802, while the sidewall 804 extends around the fluid rotational axis 826 to fully enclose the fluid rotational axis 826. According to the present example, the sidewall 804 is curved to surround the fluid rotational axis 826 to define a generally cylindrical chamber 842. This enables the first sidewall segment 810 and second sidewall segment 812 of the same sidewall 804 to be arranged radially relative to one another to define the curved flow channel 808. Each sidewall segment 810, 812 is curved about the fluid rotational axis 826. That is to say, the first sidewall segment 810 defines a first arc with a first radius, the second sidewall segment 812 defines a second arc with a second radius, the first radius being greater than the second radius so that the sidewall segments 810, 812 are radially spaced apart from another. This ensures that there is a good symmetric distribution of the tangential and radial velocities of the flow field in the radial direction and an even distribution of the velocity profiles in the vertical axis.

The sidewall 804 of the fluid tank 802 extends parallel to the fluid rotational axis 826, and the sidewall 804 extends around the fluid rotational axis 826 to define a spiral centred on the fluid rotational axis 826. That is to say, the separation between the sidewall 804 and the fluid rotational axis 826 differs for different angular positions around the fluid rotational axis. Thus a spiral may be defined, according to which the separation between the sidewall 804 and the fluid rotational axis 826 continuously decreases about the fluid rotational axis 826. The spiral may be, for example, a logarithmic spiral, an Archimedean spiral or a hyperbolic spiral. The sidewall 804 of the fluid tank 802 may define a spiral centred on the fluid outlet port 110.

Hence the first fluid intake duct 806 may be interfaced with an outer surface 816 of the fluid tank 802 to communicate the first fluid 202 along the outer surface 816, and the first fluid intake duct 806 may be arranged to inject fluid into the fluid tank 802 so that a vortex is generated about the fluid rotational axis 826.

In examples where present, the filter module flow path offtake port 112 (and hence the filter module flow inlet port 406), may be provided along the first flow path 104 in the first fluid intake duct 806, the curved flow channel 808 and/or the fluid tank 802. That is to say, the filter module flow path offtake port 112 (and hence the filter module flow inlet port 406) may be provided along the first flow path 104 between the inlet to the first fluid intake duct 806 and upstream of the fluid outlet port 110 to thereby divert a proportion of the first fluid 202 flowing along the first flow path 104 into the filter module unit 400 so that it flows along the filter module flow path 404.

The filter module flow inlet port 406 may be provided along the first flow path 104 in the first fluid intake duct 806 the curved flow channel 808 and/or the fluid tank 802. That is to say the filter module flow inlet port 406 may be provided along the first flow path 104 between the inlet to the first fluid intake duct 806 and upstream of the fluid outlet port 110 to thereby divert a proportion of the first fluid 202 flowing along the first flow path 104 into the filter module unit 400 so that it flows along the filter module flow path 404.

As shown in the example of figure 13, and in examples where present, the filter module flow path offtake port 112 (and hence the filter module flow inlet port 406) may be provided along the first flow path 104 between the first fluid inlet port 106 and the first fluid intake duct 806. That is to say, the filter module flow path of port 112 (and hence the filter module flow inlet port 406) may be provided along the pump duct 818 to thereby divert a proportion of the first fluid 202 flowing along the first flow path 104 defined by the pump duct 818 into the filter module unit 400 so that it flows along the filter module flow path 404. A plurality of a filter module units 400 may be installed in this configuration around the circumference of the pump duct 818. This configuration may be highly advantageous as the filter module flow path offtake port 112 (and hence the filter module flow inlet port 406) is provided in a location of high pressure. Also such an arrangement is easily provided as a retrofit to existing systems.

As shown in the example of figure 13, the filter module flow inlet port 406 may be provided along the first flow path 104 between the first fluid inlet port 106 and the first fluid intake duct 806. That is to say, the filter module flow inlet port 406 may be provided along the pump duct 818 to thereby divert a proportion of the first fluid 202 flowing along the first flow path 104 defined by the pump duct 818 into the filter module unit 400 so that it flows along the filter module flow path 404.

A plurality of a filter module units 400 may be installed in this configuration around the circumference of the pump duct 818. This configuration may be highly advantageous as the filter module flow inlet port 406 is provided in a location of high pressure. Also such an arrangement is easily provided as a retrofit to existing systems.

The filter module concentrate outlet port 410 may be provided along the first flow path 104 in the first fluid intake duct 806, the curved flow channel 808 and/or (as shown in figures 1 to 10) the fluid tank 802 to thereby deliver concentrate from the filter module flow path 404 to the first flow path 104.

As shown in figures 1 to 10 the filter module concentrate outlet port 410 may be provided proximate to the second fluid inlet port 108 to thereby deliver concentrate to the first flow path 104.

As shown in figure 13, the filter module concentrate outlet port 410 may be provided along the first flow path 104 between the first fluid inlet port 106 and the first fluid intake duct 806 to thereby deliver concentrate to the first flow path 104. That is to say, filter module concentrate outlet port 410 may be provided along the pump duct 818 to thereby deliver concentrate to the first flow path 104.

In a further example (not shown) the filter module flow path offtake port 112 (and hence the filter module flow inlet port 406) may be provided along the pump duct 818 and the filter module concentrate outlet port 410 may be provided on the curved flow channel 808 and/or the fluid tank 802 to thereby deliver concentrate from the filter module flow path 404 to the first flow path 104.

In another example, as shown in figures 11, 12 the filter module flow path 404 may bypass the first flow path 104 and bypass the fluid outlet port 110 such that it delivers concentrate directly to the first fluid source 200 (i.e. the first fluid reservoir 902). Put another way, the filter module flow path 404 may bypass the first flow path 104 downstream of the filter module flow inlet port 406 such that the filter module flow path 404 is configured to deliver concentrate directly to the first fluid source 200. That is to say, concentrate outlet port 410 may be located so that it discharges into the first fluid source 200 (i.e. the first fluid reservoir 902) without being returned to the first flow path 104. The concentrate outlet port 410 may be located such that concentrate is directed to flow horizontally away from the fluid treatment apparatus 100 or vertically at the side of the fluid treatment apparatus 100.

As shown in the figures, the filter module unit 400 may be supported by the first fluid intake duct 806 and/or the fluid tank 802. In an alternative example the filter module unit 400 may be supported by a dedicated support structure (not shown).

As shown in figures 1, 7, 9 the filter module flow path 404 may comprise a spiral section 430 with the filter module flow inlet port 406 spaced apart from the concentrate outlet port 410 by the spiral section 430. This increases the length of the filtrate flow path 416 while keeping the filter module unit 400 a compact size.

As shown in figures 1, 2, 4 to 8, the spiral section 430 may extend in a plane, decreasing in radius from filter module flow inlet port 406 to the concentrate outlet port 410. In such examples the concentrate outlet port 410 is located towards the centre of the spiral and the filter module flow inlet port 406 is radially outward of the concentrate outlet port 410.

The fluid treatment apparatus 100 may comprise at least two filter module units 400 provided in parallel either side-by-side (as shown in figure 9) and/or with one (or more) stacked on top of another (stacked and horizontal arrays) as shown in figure 10.

The filter module unit 400 may take a different shape form such as square, rectangular or may occupy the full external surface of the fluid tank 802.

The fluid outlet port 110 may be defined by (e.g. provided in) the fluid tank 802. That is to say, the fluid outlet port 110 may define a fluid exit path from the fluid tank 802.

As shown in figures 2, 4 to 6, 8, 10, 12, 13, the fluid treatment apparatus 100 may further comprise a fluid outlet duct 820 arranged in flow communication with the fluid outlet port 110 and terminating in a duct exit 822. That is to say, the fluid outlet port 110 may exhaust directly into the fluid outlet duct 820. The fluid outlet duct 820 may comprise a divergent section 824 such that the fluid outlet duct exit 822 has an internal cross-sectional area which is larger than the internal cross-sectional area of the fluid outlet port 110. The fluid outlet duct 820 may diverge (i.e. grow in internal cross-sectional area) from where it extends from the fluid outlet port 110. Hence at the interface of the fluid outlet port 110 and the fluid outlet duct 820, the fluid outlet port 110 and the fluid outlet duct 820 may have the same internal cross-sectional area (i.e. the same flow area).

Alternatively, at the interface of the fluid outlet port 110 and the fluid outlet duct 820, the fluid outlet port 110 may have a smaller internal cross-sectional area than the fluid outlet duct 820.

As shown in figure 4, when the fluid treatment apparatus 100 is assembled in situ as part of the fluid treatment system 900, the fluid outlet duct exit 822 may be submerged in the first fluid 202. The outlet duct exit 822 is submerged beneath the surface of the first fluid in the first fluid reservoir 902 to deliver the mix of first fluid 202 and second fluid 302 to the first fluid reservoir 902. In examples in which the second fluid 302 is air, a vortex of liquid is formed with an air core extending there through, resulting in a discharge of aerated liquid from the outlet duct exit 822.

As illustrated in figures 2, 4, the second fluid inlet port 108, the fluid outlet port 110 and the duct exit 822 may be provided in series along a common axis 826. The common axis 826 may also be the fluid rotational axis 826 in the fluid tank 802 (i.e. the axis around which fluid in the fluid tank 802 rotates). The second fluid inlet port 108, the fluid outlet port 110 and the duct exit 822 may be concentric (i.e. arranged concentrically). The filter module spiral section 430 may be centred on the common axis 826. The filter module spiral section 430 may be concentric (i.e. arranged concentrically) with the second fluid inlet port 108, the fluid outlet port 110 and the duct exit 822.

The second fluid inlet port 108 and the fluid outlet port 110 are arranged to be concentric. More particularly, the second fluid inlet port 108 and the fluid outlet port 110 are centred on the fluid rotational axis 826 at opposite ends of the fluid tank 802.

As illustrated in figure 14, the sidewall 804 of the fluid tank 802 may define a spiral centred on the common axis 826. Hence the internal surface 814 of the fluid tank 802 may define a spiral flow path centred on the common axis 826. The internal surface 814 of the fluid tank 802 may define a spiral flow path centred on the fluid outlet port 110.

As illustrated in figures 1, 8, 14 a second fluid flow control valve 460 may be provided in fluid communication with the second fluid inlet port 108. The second fluid flow control valve 460 may be operable to control the flowrate through the second fluid inlet port 108. The control system 700 may be operable to adjust the flowrate through the second fluid inlet port 108 by controlling the second fluid flow control valve 460. The control system 700 may be operable to fully close the second fluid inlet port 108.

The second fluid flow control valve 460 is operable to close the second fluid inlet port 108 partially or completely to reduce the flowrate through the second fluid inlet port 108. That is to say, the second fluid flow control valve 460 may be adjustable between an opened configuration, a partially closed configuration, and a fully closed configuration.

As illustrated in the example of figure 6, the fluid treatment apparatus 100 may further comprise one or more fluid release lines 160 in fluid communication with the first flow path 104 between the first fluid inlet port 106 and the second fluid inlet port 108. The (or each) fluid release line 160 is configured to convey surplus concentrate from the fluid reservoir 902 (for example when the concentration of concentrate is above a predetermined number.

As illustrated in figure 4, the fluid treatment system 900 may further comprise a first fluid level sensor 904, 906 configured to detect the level of the first fluid 202 and generate a signal 924, 926 indicative of the level of the first fluid 202 in the first fluid reservoir 902. Two examples of first fluid level sensors 904, 906 are illustrated in figure 4, either one of which or both may be provided as part of the fluid treatment apparatus 100 and/or fluid treatment system 900. In a first example the first fluid level sensor 904 may be provided as part of the reservoir 902, for example measuring the first fluid level 202 in the first fluid reservoir 902 directly (for example by a sensor or indicator means in contact with the first fluid 202. In a second example the first fluid level sensor 906 may be provided on the structure of the fluid treatment apparatus 100 (for example on the underside of the housing 102 or further static structure which supports the housing) and measures the distance to the surface of the first fluid 202 so that the level of the first fluid 202 in the first fluid reservoir 902 can be inferred. The control system 700 may be operable to receive the signal 924, 926 indicative of the level of the first fluid 202 202 in the first fluid reservoir 902 and, in dependence on the signal 924, 926 indicative of the level of the first fluid 202 in the first fluid reservoir 902, control the filtrate flow control valve 420 to regulate flow rate of filtrate in the fitter module filtrate flow path 416.

The fluid treatment system 900 is operable such that if the level of the first fluid 202 in the first fluid reservoir 902 is below a first predetermined value then the control system 700 is configured to control the filtrate flow control valve 420 such to reduce and/or stop the filtrate flow rate along the filter module filtrate flow path 416.

The first fluid source 200 may be a source of liquid, where the source is a free flowing (for example from a river, or down a duct from an elevated reservoir) or pumped under pressure source (for example from a pressurised or pumped source). In other examples the first fluid 202 may be a gas, delivered from a pressurised or pumped source. The second fluid source 300 may be the local atmosphere/environment, drawing in gaseous air under the action of the first fluid 202, or a liquid held in a reservoir drawn into the fluid tank 802 by the action of the first fluid 202, or gas or liquid from a pressurised or pumped source delivered into the fluid/swirl tank 802 independent of the flow characteristics of the first fluid 202. The second fluid source 300 may also comprise a supply of particles, such as powdered chemicals, which are drawn into the fluid tank alongside the second fluid.

The basic operation of the fluid treatment apparatus 100 of the present disclosure is described as follows. During operation the first fluid 202, which is pumped by the fluid pump 600, is supplied to the first fluid intake duct 806. The first fluid 202 (or "primary fluid"), which is to be treated or mixed, travels through the fluid intake duct 806 and is delivered to the fluid tank 802. In particular, the first fluid intake duct 806 is provided substantially on a tangent to the sidewall 804 of the fluid tank 802 and aligned to deliver the first fluid 202 to the internal surface 814 of the sidewall 804. Thus, the first fluid 202 is subjected to swirl and circulation about the fluid rotational axis 826, promoting the formation of a vortex. As first fluid 202 travels through the first fluid inlet port 106, the first fluid 202 is confined to the curved flow channel 808 formed between the first sidewall segment 810 and the second sidewall segment 812 to aid the transition from the linear flow through the first fluid intake duct 806 and the vortex flow within the fluid tank 802. Accordingly, the curved flow channel 808 guides flow that is injected into the fluid tank 802, and the curved flow channel 808 separates the flow that is being injected into the fluid tank 802 from a vortex within the fluid tank 802.

The flow of first fluid 202 causes a pressure differential as a result of which the second fluid 302 (or "secondary fluid") is drawn into the fluid tank 802. That is to say, the second fluid 302 is drawn in under the action of the first fluid 202. This causes the first fluid 202 and the second fluid 302 to cooperate to generate a vortex about the fluid rotational axis 826.

The flow comprises a vortex of the first fluid 202 swirling around a central core of the second fluid 302, which is a quasi-cylindrical region centred over the outlet port 110. The vortex is maintained as the first fluid 202 and the second fluid 302 exit the fluid tank 802 through the fluid outlet port 110, such that the vortex also extends through the fluid outlet duct 820 in the form of an annular jet. More particularly, the outlet duct 820 maintains the stability of the vortex and channels it to the first fluid reservoir 902.

Ultimately, the mix of fluids 202, 302 passes through the duct exit 822. In some examples the duct exit 822 is located beneath the surface of the first fluid reservoir 902. Such an arrangement enables mixing and, as the case may be, aeration. With the duct exit 822 located beneath the surface of the first fluid 202, there is no aerodynamic connection between the second fluid inlet port 108 and the underside of the vortex.

Conversely, there is first fluid connection between the vortex chamber and the receiving fluid reservoir 902. Thus, as the first fluid 202 travels from the fluid tank 802, the annular jet entrains second fluid 302, which is further improved by the plunging annular jet inside the outlet duct 820.

Where the second fluid 302 is buoyant when submerged in the first fluid 202, such as in the case of air (i.e. second fluid 302) and wastewater (i.e. first fluid 202), a bubble column is formed within the outlet duct 820. The bubble column contains bubbles of the second fluid 302 which remain in suspension within the outlet duct 820 for a prolonged period of time, neither escaping through the duct exit 822 nor the fluid outlet port 110, to further improve mixing and mass transfer.

By controlling the second fluid flow control valve 460, the flowrate of the second fluid 302 may be reduced to ensure optimised mixing ratio. Moreover, by fully closing the second fluid flow control valve 460, the vortex generator apparatus 100 is brought from a first operation mode to a second operation mode. In the first operation mode, the vortex generator apparatus 100 carries out multi-phase fluid mixing, while in the second operation mode single-phase mixing (or "pure mixing") is carried out.

Where the second fluid flow control valve 460 is partially or fully closed, the second fluid 302 cannot be replaced within the fluid tank 802 and the outlet duct 820. This results in the generation of a partial vacuum, causing the first fluid 202 surface to rise within the fluid tank 802.

Where the second fluid flow control valve 460 is partially closed, this results in a limited multiphase flow. Where the second fluid flow control valve 460 is fully closed, a purely single-phase flow is generated.

As the first fluid 202 passes through the vortex fluid mixing apparatus, pressure differential between the filter module flow inlet port 406 and concentrate outlet port 410 (where the latter may be exposed to the first fluid 202) the second fluid 302 or a mixture of the first fluid 202 and second fluid 302 will drive the first fluid 202 along the filter module filtrate flow path 416. The first fluid 202 may first pass through the pre-filter 428 located at or just downstream of filter module flow inlet port 406 which serves to inhibit larger solids or fibres from entering the filter module unit 400. The filter 414 of the filter unit 412 may comprise a form of semi-permeable barrier (i.e. a membrane) that allows the solvent and some particles to pass through while restricting the passage of other particles during the filtration process (as illustrated in figure 3). As illustrated in figure 4, the filter module unit 400 may comprise a filtrate flow control valve 420 provided in the filter module filtrate flow path 416 to regulate flow pressure in the filter module filtrate flow path 416 and thus the filtrate flow rate along the filter module filtrate flow path 416.

In a third mode of operation the filtrate flow control valve 420 is closed so that there is no flow along the filter module filtrate flow path 416, and hence no filtration is occurring.

In a fourth mode of operation, the filtrate flow control valve 420 is open so that there is flow along the filter module filtrate flow path 416, and hence filtration occurs. The difference in pressure across the filter 414 forces the components that are smaller than the filter membrane pores pass through the membrane as "filtrate" or "permeate". The remaining components are retained as "concentrate" or "retentate". The filtrate will flow along the filter module filtrate flow path 416 and -20 -discharge as final treated effluent. The retentate or concentrate will return to the fluid reservoir 902 via filter module concentrate flow path 418. As set out above, the concentrate may be delivered directly to the fluid reservoir 902 or via part of the first flow path 104.

The filtrate flow pressure sensor 422 provided in the filter module filtrate flow path 416 is operable to indicate when the filter module unit 400 is fouled. When fouled, a backwash can be performed by flushing clean water contents (with optional chemical additives) in a reverse fashion through the filter module filtrate flow path 416. Other typically used membrane backwash sequences or methods may also be used with the filter during operation. The filtrate flow pressure sensor 422 may be used to indicate and control the filtrate flowrate through the system by operation of the filtrate flow control valve 420.

The fluid treatment apparatus 100 may be operated to continuously filter by monitoring the pressure and filtrate flow to align with required wastewater discharges accordingly.

The fluid treatment apparatus 100 may be operated to utilise the first fluid level sensor 904, 906 which monitors the first fluid 202 level. The control system 700 may be operated to receive the signal 924, 926 indicative of the level of the first fluid 202 in the first fluid reservoir 902 and, in dependence on the signal 924, 926 indicative of the level of the first fluid 202 in the first fluid reservoir 902 control the filtrate flow control valve 420 to regulate flow rate of filtrate in the filter module filtrate flow path 416.

Set points (e.g. level values) can be assigned to start filtration and end filtration accordingly to ensure treatment is carried out in by the fluid treatment apparatus 100. This batch treatment can be configured for a quasi-completely mixed application (by ensuring small first fluid 202 level changes between filtration discharges) or by allowing larger volume filtrate discharges.

Additionally or alternatively, a control loop may be utilised in to target a specific water level of the first fluid 202 which thus controls the filtrate discharged volume. Hence, for examples, the fluid treatment system 900 may be operable such that if the level of the first fluid 202 is below a first predetermined value then the control system 700 is configured to control the filtrate flow control valve 420 such to reduce and/or stop the filtrate flow rate along the filter module filtrate flow path 416.

Since the fluid treatment apparatus 100 of the present disclosure is operable to pressurise the first fluid 202 as it passes along the first flow path 104, it is operable to drive flow through the filter module unit 400 to drive a filtration process. Hence the fluid treatment apparatus 100 of the present disclosure is configured to filter fluid and mix (e.g. aerate) fluid at the same time in the same fluid reservoir 902.

In some examples the filter module unit 400 is mounted above the first fluid level, and hence is accessible for easy maintenance and replacement. Even in the examples in which the -21 -filter module unit 400 is submerged (e.g. as shown in figure 13) the units are easier to remove and replace than in systems of the related art.

The fluid treatment apparatus of the present disclosure enables gradual, or batch fed treatment through filtration to enable the production of high quality effluent in a membrane bioreactor (MBR) process (or other wastewater treatment processes requiring filtration) without the need for membrane cartridges and energy intensive coarse bubbles of the related art. The fluid treatment apparatus 100 of the present disclosure provides effective oxygen transfer in higher solids conditions and is configured to avoid fouling/clogging issues. Additionally the fluid treatment apparatus 100 of the present disclosure uses significantly less energy to operate than examples of the related art.

Hence there is provided a fluid treatment apparatus with a filtering system which is easier and quicker to maintain, and enables a system which is more compact, more reliable and more energy efficient than examples of the related art.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

-22 -CLAIMS1 A fluid treatment apparatus (100) comprising: a housing (102) which defines a first flow path (104), the housing (102) comprising: a first fluid inlet port (106) for fluid communication with a first fluid source (200); a second fluid inlet port (108) for fluid communication with a second fluid source (300); a fluid outlet port (110) for fluid delivery to the first fluid source (200); the second fluid inlet port (108) being located along the first flow path (104) between the first fluid inlet port (106) and the fluid outlet port (110); the fluid treatment apparatus (100) further comprising a filter module unit (400), the filter module unit (400) comprising: a filter module flow inlet port (406), the filter module flow inlet port (406) being in fluid communication with the first flow path (104); a filtrate outlet port (408) for fluid communication with a filtrate receiving apparatus (500); a concentrate outlet port (410) for fluid communication with the first fluid source (200); the filter module unit (400) defining a filter module flow path (404) which extends from the filter module flow inlet port (406) to the filtrate outlet port (408) and the concentrate outlet port (410); and a filter unit (412) which defines a section of the filter module flow path (404) and divides the filter module flow path (404) into a filtrate flow path (416) and a concentrate flow path (418), the filter module filtrate flow path (416) extending from the filter unit (412) to the filtrate outlet port (408), and the filter module concentrate flow path (418) extending from the filter unit (412) to the concentrate outlet port (410).
2 A fluid treatment apparatus (100) as claimed in claim 1 further comprising a filter module flow path offtake port (112) located along the first flow path (104) between the first fluid inlet port (106) and the second fluid inlet port (108); the filter module flow inlet port (406) being in fluid communication with the first flow path (104) via the filter module flow path offtake port (112).

-23 - 3 A fluid treatment apparatus (100) as claimed in claim 2 wherein a debris removal feature (140) is provided upstream of the filter module flow path offtake port (112), configured to alter the fluid flow around the filter module flow path offtake port (112) to thereby bias debris flow along the first flow path (104) rather than the filter module flow path (404).

4 A fluid treatment apparatus (100) as claimed in claim 2 or claim 3 wherein the filter module flow path offlake port (112) is provided with a pre-filter (428) upstream of and in series with the filter module flow path (404).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 4 further comprising a fluid pump (600) configured for fluid communication with the first fluid source (200) and the first fluid inlet port (106) to thereby deliver pressurised first fluid (202) to the first flow path (104). 8

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 5 wherein the filter module unit (400) comprises a filtrate flow control valve (420) provided in the filter module filtrate flow path (416).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 6 wherein the filtrate outlet port (408) is provided along the filter module flow path (404) between the filter module flow inlet port (406) and the concentrate outlet port (410).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 7 wherein the filter module unit (400) comprises a concentrate flow control valve (426) provided in the filter module concentrate flow path (418).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 8 wherein the filter module unit (400) comprises a filtrate flow pressure sensor (422) provided in the filter module filtrate flow path (416).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 9 wherein the filter module filtrate flow path (416) is in flow communication with a vacuum pump (610) -24 -configured and operable to draw filtrate along the filtrate flow path (416) to the filtrate outlet port (408).

11 A fluid treatment apparatus (100) as claimed in any one of claims 1 to 10 further comprising a vortex generator apparatus (800) which comprises: a fluid tank (802) defined by a sidewall (804); a first fluid intake duct (806) in fluid communication with the first fluid inlet port (106), and the first fluid intake duct (806) extending to a curved flow channel (808) defined between a first sidewall segment (810) of the fluid tank sidewall (804) and a second sidewall segment (812) of the fluid tank sidewall (804); and the first fluid intake duct (806) is provided substantially on a tangent to the first sidewall segment (810) of the fluid tank (802) sidewall (804) and aligned to deliver the first fluid (202) to an internal surface (814) of the first sidewall segment (810). 12

The fluid treatment apparatus (100) as claimed in claim 11, wherein the first fluid intake duct (806) is interfaced with an outer surface (816) of the fluid tank (802) to communicate the first fluid (202) along the outer surface (816).

A fluid treatment apparatus (100) as claimed in any one of claims 11, 12 wherein the filter module flow inlet port (406) is provided along the first flow path (104) in the first fluid intake duct (806), the curved flow channel (808) and/or the fluid tank (802).

A fluid treatment apparatus (100) as claimed in any one of claims 11, 12 wherein the filter module flow inlet port (406) is provided along the first flow path (104) between the first fluid inlet port (106) and the first fluid intake duct (806).

A fluid treatment apparatus (100) as claimed in any one of claims 11 to 14 wherein the filter module concentrate outlet port (410) is provided along the first flow path (104) in the first fluid intake duct (806), the curved flow channel (808) and/or the fluid tank (802).

A fluid treatment apparatus (100) as claimed in claim 15 wherein the filter module concentrate outlet port (410) is provided proximate to the second fluid inlet port (108).

-25 - 17 A fluid treatment apparatus (100) as claimed in any one of claims 11 to 14 wherein the filter module concentrate outlet port (410) is provided along the first flow path (104) between the first fluid inlet port (106) and the first fluid intake duct (806).

18 A fluid treatment apparatus (100) as claimed in any one of claims 1 to 14 wherein the filter module flow path (404) bypasses the first flow path (104) downstream of the filter module flow inlet port (406) such that the filter module flow path (404) is configured to deliver concentrate directly to the first fluid source (200). 19 23

A fluid treatment apparatus (100) as claimed in any one of claims 11 to 18 wherein the filter module unit (400) is supported by the first fluid intake duct (806) and/or the fluid tank (802).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 19 wherein the filter module flow path (404) comprises a spiral section (430) with the filter module flow inlet port (406) spaced apart from the concentrate outlet port (410) by the spiral section (430).

A fluid treatment apparatus (100) as claimed in claim 20 wherein the spiral section (430) extends in a plane, decreasing in radius from filter module flow inlet port (406) to the concentrate outlet port (410).

A fluid treatment apparatus (100) as claimed in any one of claims 1 to 21 wherein the fluid treatment apparatus (100) comprises at least two filter module units (400) provided in parallel and side-by-side and/or with one stacked on top of another.

The fluid treatment apparatus (100) as claimed in claim 11 and any of claims 12 to 22 when dependent on claim 11, wherein the fluid outlet port (110) is defined by the fluid tank (802), and the fluid treatment apparatus (100) further comprises: a fluid outlet duct (820) arranged in flow communication with the fluid outlet port (110) and terminating in a duct exit (822), and the fluid outlet duct (820) comprising a divergent section (824) such that the fluid outlet duct exit (822) has an internal cross-sectional area which is larger than the internal cross-sectional area of the fluid outlet port (110).

-26 -25 29 The fluid treatment apparatus (100) as claimed in claim 23, wherein the second fluid inlet port (108), the fluid outlet port (110) and the duct exit (822) are provided in series along a common axis (826).

The fluid treatment apparatus (100) as claimed in claim 11 and any of claims 12 to 24 when dependent on claim 10 wherein the sidewall (804) of the fluid tank (802) defines a spiral centred on the fluid outlet port (110).

The fluid treatment apparatus (100) as claimed in any one of claims 1 to 25 wherein the filter module unit (400) is provided outside of the housing (102) such that the filter module unit (400) is spaced apart from the first flow path (104) by the housing (102).

The fluid treatment apparatus (100) as claimed in any one of claims 1 to 25 wherein the filter module unit (400) is provided in the first flow path (104).

The fluid treatment apparatus (100) as claimed in claim 11 and any one of claims 12 to 27 when dependent on claim 11 wherein the first fluid intake dud (806) comprises a divergent section (830).

The fluid treatment apparatus (100) as claimed in any one of the preceding claims wherein a second fluid flow control valve (460) is provided in fluid communication with the second fluid inlet port (108) and is operable to control the flowrate through the second fluid inlet port (108).

30 The fluid treatment apparatus (100) as claimed in any one of the preceding claims further comprising a fluid release line (160) in fluid communication with the first flow path 004) between the first fluid inlet port (106) and the second fluid inlet port 008).

31 A fluid treatment system (900) comprising a fluid treatment apparatus (100) as claimed in any one of claims 1 to 30 and a first fluid reservoir (902) of the first fluid (202), wherein the first fluid inlet port (106) and the fluid outlet port (110) of the fluid treatment apparatus (100) are in fluid communication with the first fluid (202) in the first fluid reservoir (902).

-27 - 32 A fluid treatment system (900) as claimed in claim 31 further comprising a first fluid level sensor (904, 906) configured to detect the level of the first fluid (202) in the first fluid reservoir (902) and generate a signal (924, 926) indicative of the level of the first fluid (202) in the first fluid reservoir (902); and the control system (700) operable to receive the signal (924, 926) indicative of the level of the first fluid (202) in the first fluid reservoir (902) and, in dependence on the signal (924, 926) indicative of the level of the first fluid (202) in the first fluid reservoir (902), control the filtrate flow control valve (420) to regulate flow rate of filtrate in the filter module filtrate flow path (416).

33 A fluid treatment system (900) as claimed in claim 32 configured such that if the level of the first fluid (202) in the first fluid reservoir (902) is below a first predetermined value then the control system (700) is operable to control the filtrate flow control valve (420) such to reduce and/or stop the filtrate flow rate along the filter module filtrate flow path (416).

34 A fluid treatment system (900) comprising as claimed in claim 32 or claim 33 when dependent on claim 23 wherein the fluid outlet duct exit (822) is submerged in the first fluid (202).