Patent Description:
Known heating and cooling systems comprise a fluid circuit through which a fluid circulates under pressure. An example of this type of system is a closed circuit central heating system, in which system water flows in a loop from a boiler, through a series of radiators or heat emitters, and then back to the boiler.

Systems of this type are typically manufactured from steel and other common metals. In such systems, material surfaces are exposed to the circulated fluid. A problem that is commonly associated that these systems is the corrosion of metal that is in contact with the system fluid.

System corrosion results in contamination of the circulated water with corrosion particles, such as rust, detritus and other undesirable debris. The presence of corrosion particles within the circulated liquid negatively impacts system performance and causes damage. Unless the corrosion particles are captured and removed from the contaminated circulated liquid, system components can become clogged or blocked, leading to a significant loss of system efficiency, further system deterioration from leaks, and eventually total system failure.

When the performance efficiency of a heating or cooling system reduces due to the effects of corrosion contamination, both the amount of energy required to operate the system and the amount of carbon dioxide (CO2) emitted by the system increases. It is therefore desirable from economic and environmental perspectives to prevent or inhibit the detrimental effect of corrosion particles within the circulating liquid.

A known device for use in removing corrosion particles from the circulating fluid is a strainer (also termed a pipeline strainer). The strainer is connected to the fluid circuit piping, directly in-line with the fluid flow, and functions to mechanically remove unwanted solids from the system fluid. When installed, fluid flows through a screen within the strainer, which acts as a physical filter. Particles in the system fluid that are over a certain size are trapped by the screen, and captured particles are retained within the strainer for subsequent removal.

Strainers are typically installed upstream of equipment to be protected. For example, a strainer may be installed upstream of a pump to prevent larger pieces of debris from fouling the impeller, which could result in a blockage or damage. By way of further example, a strainer may be used upstream of a boiler, a heat exchanger, or a large and/or expensive item in a system.

A first type of prior art strainer is known as a Y-type strainer. The body of a Y-type strainer has first and second branches providing an inlet and an outlet, and a third intermediate branch providing a pocket for a screen that intersects the fluid flow path between the inlet and outlet, such that fluid flowing through the body passes through the screen. The screen is typically cylindrical and made from a metal perforated sheet or mesh. In use, fluid flows into an open end of the cylindrical screen and any particles that are too big to flow through the openings, such as rust and detritus particles, are trapped inside for subsequent removal. In this way, contaminant particles over a certain size are separated from the circulating fluid as it flows through the strainer. Over time, however, the particles captured within the cylindrical screen build up and inhibit throughflow. To prevent problems arising from clogging or blocking of the screen by caught particles, routine maintenance is required to remove the collected detritus from within the strainer. However, unlike some filters, the screen can be cleaned and reused.

A typical screen has openings dimensioned to prevent passage therethrough of particles having a particle size equal to or greater than <NUM> microns. Therefore, particles having a particle size less than <NUM> microns are not prevented from flowing through the strainer and back into circulation. It is known for these smaller particles to settle in 'low flow' areas, for example at the bottom of radiators and pipes of a heating system. Further, it is known for rust particles, which are relatively very small, to combine with scale deposits to form a sludge-like substance (generally termed sludge). This is particularly prevalent in areas of particle settlement. Sludge is a common problem within heating systems, and can block pipework and develop into large clumps in the bottom of radiators. Sludge deposits or clumps at the lower end of a radiator cause a localised reduction in heat transmission (known in the industry as a cold spot). The presence of such cold spots increases energy usage and places the system under operational strain.

Japanese Patent Publication No. <CIT> discloses a strainer including a housing which is equipped with a mounting opening in a flow passage connecting to an inflow port and an outflow port and which is equipped with a cap detachably mounted in the mounting opening, a screen detachably equipped at the mounting opening in the flow passage, a cover member made of a non-magnetic body that closes an opening of the mounting opening side of the screen and seals the mounting opening in the housing, and a cylindrical permanent magnet arranged in a magnet housing chamber formed between the cover member and the cap.

According to a first aspect there is provided a strainer for use in fluid piping, said strainer comprising: a body for connection to a fluid piping inflow conduit and to a fluid piping outflow conduit, the body defining an interior chamber, a fluid inlet port and a fluid outlet port, and the body defining a fluid flow path between the fluid inlet port and the fluid outlet port that extends through the interior chamber; a screen collector removably locatable in the body, within the fluid flow path; and a permanent magnet collector removably locatable in the body; said body defining a collector port open to the interior chamber through which the screen collector and the permanent magnet collector can be removably inserted into the body; and the strainer comprises a first cap releasably engageable with the body to selectively seal the collector port, the first cap made from a non-magnetic material and defining a permanent magnet collector housing chamber into which the permanent magnet collector is removably locatable; characterised in that: the strainer further comprises a second cap releasably engageable with the first cap to selectively seal the permanent magnet collector housing chamber and form a collector port cap assembly that is releasably engageable with the body of the strainer by releasably engaging the first cap to the body to seal the collector port, the second cap made from a non-magnetic material; and said permanent magnet collector is releasably securable to said second cap to form a cap and magnet assembly that is detachable from the first cap while the first cap is secured to the body of the strainer.

The screen collector may comprise a substantially tubular body having an open fluid inflow end, the substantially tubular body locatable within the fluid flow path such that fluid flowing from the fluid inlet port towards the fluid outlet port enters the substantially tubular body through the open fluid inflow end.

The permanent magnet collector may be removably positionable within the substantially tubular body of the screen collector.

The screen collector may define a plurality of openings dimensioned to capture particles having a particle size equal to or greater than <NUM> microns.

The body may have a Y-shape, and in which a first branch of the Y-shape comprises the fluid inlet port, a second branch of the Y-shape comprises the fluid outlet port and a third branch of the Y-shape comprises the collector port.

A fixing element may be provided for releasably securing the permanent magnet collector to the second cap.

The second cap may extend into the permanent magnet collector housing chamber of the first cap when the second cap is engaged with the first cap.

The permanent magnet may have a first end, a second end and a side wall extending between the first end and the second end, and the permanent magnet may be removably locatable within the permanent magnet collector housing chamber such that that the first end and the second end are positioned within the interior chamber of the body.

The body may be provided with first and second connection screw threads, or with first and second connection flanges, for use in connecting the body to a fluid piping inflow conduit and to a fluid piping outflow conduit.

According to a second aspect, a strainer according to the first aspect is used in fluid circuit piping of a heating or cooling system.

According to a third aspect there is provided fluid piping provided with a strainer according to the first aspect.

The invention advantageously provides a pipe line strainer with both a mechanical and a magnetic collector.

Further particular and preferred aspects of the invention are set out in the accompanying dependent claims.

The present invention will now be more particularly described, with reference to the accompanying drawings, in which:.

Example embodiments are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the apparatus, systems and processes described herein. It is to be understood that embodiments can be provided in many alternate forms and the invention should not be construed as limited to the examples set forth herein but by the scope of the appended claims.

A strainer <NUM> is shown in <FIG>. The strainer <NUM> is suitable for use in fluid piping, for example fluid circuit piping of a heating or cooling system.

In <FIG> and <FIG>, the strainer <NUM> is shown in a fully assembled condition.

Referring to <FIG>, strainer <NUM> comprises a body <NUM> for connection to connection to a fluid piping inflow conduit and to a fluid piping outflow conduit, as will be described in further detail below with reference to <FIG>.

The body <NUM> defines an interior chamber <NUM>, a fluid inlet port <NUM> and a fluid outlet port <NUM>. The body <NUM> defines a fluid flow path, indicated by arrow <NUM>, between the fluid inlet port <NUM> and the fluid outlet port <NUM> that extends through the interior chamber <NUM>. The body <NUM> is arranged such that fluid, such as circulating liquid of a heating or cooling system, flowing therethrough from the fluid inlet port <NUM> to the fluid outlet port <NUM> passes through the interior chamber <NUM>.

The strainer <NUM> comprises a screen collector <NUM>. The screen collector <NUM> allows fluid to flow therethrough. The screen collector <NUM> is removably locatable in the body <NUM>. More specifically, and as shown in <FIG> and <FIG>, the screen collector <NUM> is locatable in the interior chamber <NUM>, within the fluid flow path <NUM>. The screen collector <NUM> is locatable within the body <NUM> such that fluid flowing through the strainer <NUM> from the fluid inlet port <NUM> to the fluid outlet port <NUM> passes through the screen collector <NUM>. The screen collector <NUM> is described in detail below.

The strainer <NUM> further comprises a permanent magnet collector <NUM>. The permanent magnet collector <NUM> is removably locatable in the body <NUM>. As shown in <FIG> and <FIG>, the permanent magnet collector <NUM> is positionable to collect magnetic particles from fluid flowing through the interior chamber <NUM>. The permanent magnet collector <NUM> is described in detail below.

The strainer <NUM> is arranged to mechanically capture particles having a particle size equal or greater than a predetermined size and to magnetically capture magnetic particles having a particle size less than the predetermined size. In an example, the predetermined size is <NUM> microns and particles having a particle size equal or greater than <NUM> microns are captured by the screen collector <NUM> and particles having a particle size less than <NUM> microns are captured by the permanent magnet collector <NUM>. It is to be appreciated that the predetermined size may vary between applications. Thus, the screen collector <NUM> is not limited to screening particles that are <NUM> microns or greater in size. The screen collector <NUM> can be selected to screen particles of a different particle size, for example depending on the particular intended application of the strainer <NUM>.

The permanent magnet collector thus provides an additional straining effect to that provided by the screen collector.

Strainer <NUM> is shown installed for use in <FIG>. As illustrated, the body <NUM> is connected to a fluid piping inflow conduit <NUM> and to a fluid piping outflow conduit <NUM>. Fluid flowing from the fluid piping inflow conduit <NUM> to the fluid piping outflow conduit <NUM> flows through the interior chamber <NUM> of the body <NUM>.

The body <NUM> is made from a non-magnetic material. In an example, the body <NUM> is made from a non-magnetic metal, for example stainless steel or brass. The body <NUM> may however be made from any suitable non-magnetic material or combination of non-magnetic materials.

According to the specific illustrated embodiment, the screen collector <NUM> comprises a substantially tubular body <NUM> having an open fluid inflow end <NUM>. The screen collector <NUM> may take the form of a basket. As shown, the substantially tubular body <NUM> is locatable within the fluid flow path <NUM> such that fluid flowing from the fluid inlet port <NUM> towards the fluid outlet port <NUM> enters the substantially tubular body <NUM> through the open fluid inflow end <NUM>.

In this example, the substantially tubular body <NUM> is substantially cylindrical. The substantially tubular body <NUM> has a substantially circular shaped cross section, in the direction A-A. It is to be appreciated that in alternative examples the substantially tubular body <NUM> may have any suitable alternative cross-sectional shape.

In this example, the screen collector <NUM> defines a plurality of openings <NUM> dimensioned to capture particles having a particle size equal to or greater than <NUM> microns. The screen collector <NUM> may however be arranged to capture particles of any suitable alternative size. The screen collector <NUM> is arranged to separate particles of a certain size from fluid flowing through the strainer <NUM>.

In this example, the screen collector <NUM> comprises a perforated metal sheet screen. It is to be appreciated that the screen collector could comprise any suitable alternative type of screen, for example an expanded metal sheet screen, a welded wire mesh screen, or a woven wire mesh screen. Further, the screen may be made from any suitable material or combination of materials, and is not limited to being made from metal.

The screen collector <NUM> may define any suitable number of openings <NUM>, which may be any suitable size and shape and which may include openings of different sizes and/or shapes.

In this example, the permanent magnet collector <NUM> comprises a rare-earth magnet. The permanent magnet collector <NUM> may comprise an alternative type of magnet, for example a ferrite or AlNiCo type magnet. The permanent magnet collector <NUM> may comprise one or more magnets. The permanent magnet collector <NUM> is arranged to separate magnetic particles from fluid flowing through the strainer <NUM>.

During use of the strainer <NUM>, circulating fluid flowing in the fluid piping flows from the fluid piping inflow conduit <NUM>, through the fluid inlet port <NUM> into the interior chamber <NUM>, through the screen collector <NUM> and through the fluid outlet port <NUM> to exit the interior chamber <NUM> into the fluid piping outflow conduit <NUM>.

As the fluid flows through the strainer <NUM>, particles in the fluid are captured in the interior chamber <NUM>.

Particles having a particle size that is equal to or greater than a predetermined particle size are collected by the screen collector <NUM>. Magnetic particles having a particle size less than the predetermined particle size are collected by the permanent magnet collector <NUM>. It is to be appreciated however that the permanent magnet collector <NUM> may also collect particles having a particle size that is equal to or greater than the predetermined particle size, as will know be described.

As shown, in the illustrated embodiment, the substantially tubular body <NUM> is locatable within the fluid flow path <NUM> such that fluid flowing from the fluid inlet port <NUM> towards the fluid outlet port <NUM> enters the substantially tubular body <NUM> through the open fluid inflow end <NUM>. It can be seen that the substantially tubular body <NUM> and the body <NUM>, in particular the internal profile of the body <NUM>, are arranged such that all the fluid entering the strainer <NUM> must enter the substantially tubular body <NUM> of the screen collector <NUM>. Any particles in the fluid that are too big to pass through the openings <NUM> are mechanically captured and retained within the substantially tubular body <NUM> of the screen collector <NUM>.

In this illustrated embodiment, the permanent magnet collector <NUM> is removably positionable within the substantially tubular body <NUM> of the screen collector <NUM>. With this arrangement, magnetic particles attracted to the permanent magnet collector <NUM> are retained within the substantially tubular body <NUM> of the screen collector <NUM>, along with the particles mechanically captured by the screen collector <NUM>. It is to be appreciated that any suitable alternative relative positioning of the permanent magnet collector <NUM> and the screen collector <NUM> may be utilised.

The screen collector <NUM> and permanent magnet collector <NUM> function to remove particles, such as corrosion particles, from contaminated fluid flowing through the strainer <NUM>, such that fluid exits the interior chamber <NUM> cleaner than when it entered the interior chamber <NUM>. Thus, using the strainer <NUM> upstream of an item of equipment functions to prevent contaminant particles from flowing to that item of equipment.

In this embodiment, the strainer <NUM> further comprises a permanent magnet collector housing <NUM> made from a non-magnetic material in which the permanent magnet collector <NUM> is located. Preferably, and in this example, the permanent magnet collector <NUM> is removably located in the permanent magnet collector housing <NUM>. The permanent magnet collector housing <NUM> advantageously maintains the permanent magnet collector <NUM> in a dry condition. The permanent magnet collector housing <NUM> beneficially protects the permanent magnet collector <NUM> from detrimental effects of exposure to system fluid flowing through the interior chamber <NUM>. The permanent magnet collector housing may be made from any suitable non-magnetic material or combination of non-magnetic materials.

In <FIG>, particles <NUM> are shown collected around the permanent magnet collector housing <NUM> due to a magnetic attraction between the particles <NUM> and the permanent magnet collector <NUM> located within the permanent magnet collector housing <NUM>.

In this illustrated embodiment, the body <NUM> defines a collector port <NUM> open to the interior chamber <NUM> through which the screen collector <NUM> and the permanent magnet collector <NUM> can be removably inserted into the body <NUM>.

According to the present embodiment, the body <NUM> has a Y-shape. A first branch <NUM> of the Y-shape comprises the fluid inlet port <NUM>, a second branch <NUM> of the Y-shape comprises the fluid outlet port <NUM> and a third branch <NUM> I of the Y-shape comprises the collector port <NUM>. In this illustrated example, the fluid inlet port <NUM> and the fluid outlet port <NUM> are aligned, with the first and second branches <NUM>, <NUM> of the Y-shape being arranged linearly, and the third branch <NUM> extends outwardly from a position intermediate the fluid inlet and outlet ports <NUM>, <NUM>.

In the shown arrangement, the body <NUM> comprises an internal annular shoulder <NUM> against which the substantially tubular body <NUM> of the screen collector <NUM> abuts. When the screen collector <NUM> is located within the body <NUM> as shown, the interior chamber <NUM> is, in effect, divided into three zones - a first zone upstream of the screen collector <NUM>, a second zone occupied by the substantially tubular body <NUM> of the screen collector <NUM> and a third zone downstream of the screen collector <NUM>.

In <FIG>, the strainer <NUM> is shown installed between the fluid piping inflow and outflow conduits <NUM>, <NUM> such that the first and second branches <NUM>, <NUM> of the Y-shaped body <NUM> are in a generally orientation along a virtual horizontal line and the third branch <NUM> of the Y-shaped body <NUM> points downwardly from the virtual horizontal line. With this orientation, gravity assists with the retention of collected particles within the substantially tubular body <NUM> of the screen collector <NUM>.

Further features of the present embodiment will now be described with reference to <FIG> and <FIG>.

The strainer <NUM> comprises a collector port cap assembly <NUM>. In this illustrated example, the collector port cap assembly <NUM> comprises a first cap <NUM> and a second cap <NUM>. The first cap <NUM> is releasably engageable with the body <NUM> to selectively seal the collector port <NUM>. The first cap <NUM> is made from a non-magnetic material and comprises a permanent magnet collector housing chamber <NUM> into which the permanent magnet collector <NUM> is removably locatable. The second cap <NUM> is releasably engageable with the first cap <NUM> to selectively seal the permanent magnet collector housing chamber <NUM> and is made from a non-magnetic material.

The first cap <NUM> may be releasably engageable with the body <NUM> by any suitable engagement arrangement, for example a co-operating screw thread arrangement or a snap-fit arrangement. The second cap <NUM> may be releasably engageable with the first cap <NUM> by any suitable engagement arrangement, for example a co-operating screw thread arrangement or a snap-fit arrangement.

The first cap <NUM> and the second cap <NUM> may each be made from any suitable non-magnetic material or combination of non-magnetic materials. Each of the first cap <NUM> and the second cap <NUM> may be made from a plastics material. The first cap <NUM> and the second cap <NUM> may be made from the same, or different, plastics material.

In the illustrated example, the permanent magnet collector housing chamber <NUM> is positioned centrally of the first cap <NUM>. The permanent magnet collector housing chamber <NUM> may be positioned at any suitable alternative site. As shown, the permanent magnet collector housing chamber <NUM> has an external surface <NUM>.

In this illustrated example, a fixing element <NUM> for releasably securing the permanent magnet collector <NUM> to the second cap <NUM> is provided. In this example, the fixing element <NUM> is a screw. Any suitable alternative fixing element, elements or arrangement may be utilised.

The second cap <NUM> with permanent magnet collector <NUM> secured thereto forms a cap and magnet assembly <NUM>. The cap and magnet assembly <NUM> is removable from the first cap <NUM>. According to the shown example, the first cap <NUM> can be disengaged from the second cap <NUM> and then moved away from the second cap <NUM> to withdraw the permanent magnet collector <NUM> from the permanent magnet collector housing chamber <NUM> of the first cap <NUM>. The cap and magnet assembly <NUM> can beneficially be detached from the first cap <NUM> while the first cap <NUM> is secured to the body <NUM> of the strainer <NUM>. With the permanent magnet collector housing chamber <NUM> being integral to the first cap <NUM>, which, in use, seals the collector port <NUM> of the body <NUM>, the permanent magnet collector <NUM> can thus be withdrawn from the body <NUM> without unsealing the collector port <NUM>.

<FIG> shows a cap and magnet assembly <NUM>. A strainer <NUM> is shown in <FIG>. Strainer <NUM> of <FIG> is similar to strainer <NUM> of <FIG> but comprises the cap and magnet assembly <NUM> of <FIG> instead of the cap and magnet assembly <NUM> of <FIG>. The cap and magnet assembly <NUM> of <FIG> is similar to the cap and magnet assembly <NUM> of <FIG> and will now be described with reference to <FIG>.

Cap and magnet assembly <NUM> comprises a second cap <NUM> and a permanent magnet collector <NUM>. The first cap <NUM> is made from non-magnetic material. In this example, the permanent magnet collector <NUM> is releasably securable to the second cap <NUM>. In this example, the cap and magnet assembly <NUM> comprises a reusable fixing <NUM> for releasably securing the permanent magnet collector <NUM> to the second cap <NUM>. The second cap <NUM> comprises an engagement portion for use in releasably engaging the second cap <NUM> with the first cap <NUM> of the strainer <NUM>. According to the present example, the second cap <NUM> comprises an external screw thread <NUM> for co-operating with an internal screw thread <NUM> of the first cap <NUM>. The second cap <NUM> comprises a collar <NUM>. When the second cap <NUM> of the cap and magnet assembly <NUM> is engaged with the first cap <NUM>, as shown in <FIG>, the collar <NUM> is positioned up towards the exterior of the first cap <NUM>.

As illustrated, the second cap <NUM> comprises an internal extension portion <NUM>, which extends to the side of the collar <NUM> that is presented to the first cap <NUM> when the second cap <NUM> is being engaged therewith. The internal extension portion <NUM> is dimensioned to extend into the permanent magnet collector housing chamber <NUM> of the first cap <NUM> when the second cap <NUM> is secured therewith. Thus, the second cap <NUM> extends into the permanent magnet collector housing chamber <NUM> when engaged with the first cap <NUM>.

Permanent magnet collector <NUM> has a first end <NUM>, a second end <NUM>, and a side wall <NUM> extending between the first and second ends <NUM>, <NUM>. In the present example, and as can be seen in <FIG>, the permanent magnet collector <NUM> is removably locatable within the permanent magnet collector housing chamber <NUM> such that both the first end <NUM> and the second end <NUM> are positioned within the interior chamber <NUM> of the body <NUM>. As a result, the magnetic field present all around the permanent magnet collector <NUM> is exerted within the interior chamber <NUM>. More specifically, with the illustrated arrangement of strainer <NUM>, the magnetic field applied by the permanent magnet collector <NUM> within the screen collector <NUM> is optimised. In addition, the size of the permanent magnet collector <NUM> can be effectively minimised.

In the shown example, the permanent magnet collector <NUM> is detachably attachable to free end <NUM> of the internal extension portion <NUM> of the second cap <NUM>. When the cap and magnet assembly <NUM> is received within the first cap <NUM>, the permanent magnet collector <NUM> is displaced from the underside of the collar <NUM> of the second cap <NUM> a distance <NUM> by the non-magnetic internal extension portion <NUM>. The internal extension portion <NUM> ensures that the permanent magnet collector <NUM> is inserted to the desired position within the permanent magnet collector housing chamber <NUM> when the second cap <NUM> is engaged with the first cap <NUM>. The use of the internal extension portion <NUM> ensures that magnetic material is not utilised within the strainer <NUM> at a position in which the effect of the associated magnetic field on magnetic particles within fluid flowing the internal chamber <NUM> thereof is relatively insignificant.

In this example also, the second cap <NUM> further comprises an external extension portion <NUM>, which extends to the opposite side of the collar <NUM> and that remains outside of the first cap <NUM> when the second cap <NUM> is engaged therewith. In this specific example, the external extension portion <NUM> is profiled to allow a tool to be used thereon to facilitate engagement of the second cap <NUM> with the first cap <NUM>. The external extension portion <NUM> may be profiled as a hexagonal head, with which a suitable socket can be used to effect rotation of the second cap <NUM>.

The strainer <NUM> may be provided with any suitable arrangement for use in connecting the body <NUM> to a fluid piping inflow conduit and to a fluid piping outflow conduit. In this illustrated example, the body <NUM> is provided with first and second connection screw threads <NUM>, <NUM> for use in connecting the body <NUM> to a fluid piping inflow conduit and to a fluid piping outflow conduit. In an alternative example, the body <NUM> is provided with first and second connection flanges for use in connecting the body <NUM> to a fluid piping inflow conduit and to a fluid piping outflow conduit.

It is to be appreciated that a strainer as described herein may have an alternative arrangement to that illustrated. For example, the body may define a collector port that is selectively sealable with a cap that does not form or comprise a permanent magnet collector housing chamber, in which case a separate permanent magnet collector housing may be provided.

Fluid piping may be provided with one or more of strainers as described herein. For example, strainers as described herein are usable in fluid circuit piping of a heating or cooling system, to protect one or more items of equipment, such as a pump, from contaminant particles in the circulating system water.

A method of installing fluid treatment apparatus in fluid piping will now be described. The method involves the steps of receiving strainer <NUM>, connecting the body <NUM> of the strainer <NUM> to a fluid piping inflow conduit of the fluid piping and connecting the body <NUM> of the strainer <NUM> to a fluid piping outflow conduit of the fluid piping. The method also involves the steps of locating the screen collector <NUM> within the body <NUM> of the strainer <NUM> and locating the permanent magnet collector <NUM> within the body of the strainer <NUM>. It is to be appreciated that as the screen collector <NUM> and permanent magnet collector <NUM> are removably locatable within the body <NUM> of the strainer <NUM>, the above-mentioned steps may be performed in any suitable order. For example, the screen collector <NUM> and permanent magnet collector <NUM> may be located within the body <NUM> of the strainer <NUM> before or after the body <NUM> of the strainer <NUM> is connected between fluid piping inflow and outflow conduits.

In an application, the fluid piping is fluid circuit piping of a heating or cooling system. In such an application, the strainer is usable to remove contaminants, such as corrosion particles, from the circulating system liquid. In an alternative application, the fluid piping is piping of a fuel line. In such an application, the strainer is usable to remove contaminants from a flow of fuel. The fuel may, for example, be petrol.

A method of treating fluid of fluid piping will now be described. The method involves the steps of identifying a strainer <NUM> that is installed within fluid piping following the method of installing fluid treatment apparatus in fluid piping described above, stopping fluid flow into the body <NUM>, removing, cleaning and replacing the screen collector <NUM>, removing, cleaning and replacing the permanent magnet collector <NUM>, and restarting a fluid flow into the body <NUM>. The method of treatment provided by the strainer <NUM> is that of particle capturing and regular cleaning of the screen and permanent magnet collectors <NUM>,<NUM> ensures operational efficiency of the strainer <NUM> in capturing particles from the fluid flow and improves operational efficiency of the system.

Routine maintenance of the strainer <NUM> will now be described.

During normal operation of the strainer <NUM>, particles having a particle size equal to or greater than a predetermined size that enter into the strainer <NUM> with the circulating fluid are captured by the screen collector <NUM>. These mechanically captured particles are retained in the interior chamber <NUM> until subsequently removed. Further, during normal operation of the strainer <NUM>, magnetic particles are attracted by the permanent magnet collector <NUM> and collect on the external surface <NUM> of the permanent magnet collector housing chamber <NUM> that is exposed to the circulating fluid (wet side of first cap <NUM>). These magnetically captured particles are retained in the interior chamber <NUM> until subsequently removed.

To remove material collected from the circulating fluid by the strainer <NUM>, the strainer <NUM> is isolated from fluid flow. Thus, the circulation of the system fluid into the strainer <NUM> is stopped. The first cap <NUM> is then removed from the body <NUM>. Any magnetic detritus collected will be present on the external surface <NUM> of the permanent magnet collector housing chamber <NUM>. The second cap <NUM> is then removed from the first cap <NUM>, which has the effect of withdrawing the permanent magnet collector <NUM> from the permanent magnetic collector housing chamber <NUM>. This removes the magnetic field previously applied by permanent magnet collector <NUM> to hold the collected magnetic particles on the external surface <NUM> of the permanent magnetic collector housing chamber <NUM>. With the magnetic field now absent, the collected magnetic particles fall away from the first cap <NUM>. The first cap <NUM> can be rinsed to ensure proper cleanliness, and the second cap <NUM> can then be replaced to seal the permanent magnet collector <NUM> within the permanent magnetic collector housing chamber <NUM>. With the first cap <NUM> removed from the body <NUM>, the screen collector <NUM> can be withdrawn through the collector port <NUM> and rinsed clean. The cleaned screen collector <NUM> can then be replaced in the interior chamber <NUM>. Following cleaning of the screen collector <NUM> and the permanent magnet collector <NUM>, the collector port cap assembly <NUM> can be reconnected to the body <NUM> to seal the collector port <NUM>. The strainer <NUM> may then be opened back to the system flow. It is to be appreciated that the screen and permanent magnet collectors <NUM>, <NUM> may be cleaned in any chronological order.

It is further to be appreciated that the screen and permanent magnet collectors <NUM>, <NUM> of the strainer <NUM> may be substituted, for example to change the size of the openings of the screen collector or the magnetic field applied by the permanent magnet collector.

At least the following benefits are associated with the strainer of the present invention:.

The strainer of the present invention is thus environmentally advantageous.

A strainer as described herein may have any suitable dimensions, any suitable appearance, may be made from any suitable materials or combination of materials and may be made using any suitable method, process or technique or any suitable combination of methods, processes or techniques. It is thus to be understood that any suitable material fabrication, construction and method of manufacture may be used. A strainer as described herein may be used in any suitable application.

Claim 1:
A strainer (<NUM>) for use in fluid piping, said strainer (<NUM>) comprising:
a body (<NUM>) for connection to a fluid piping inflow conduit (<NUM>) and to a fluid piping outflow conduit (<NUM>), the body (<NUM>) defining an interior chamber (<NUM>), a fluid inlet port (<NUM>) and a fluid outlet port (<NUM>), and the body (<NUM>) defining a fluid flow path (<NUM>) between the fluid inlet port (<NUM>) and the fluid outlet port (<NUM>) that extends through the interior chamber (<NUM>);
a screen collector removably (<NUM>) locatable in the body (<NUM>), within the fluid flow path (<NUM>); and
a permanent magnet collector (<NUM>) removably locatable in the body (<NUM>);
said body (<NUM>) defining a collector port (<NUM>) open to the interior chamber (<NUM>) through which the screen collector (<NUM>) and the permanent magnet collector (<NUM>) can be removably inserted into the body (<NUM>); and
the strainer (<NUM>) comprises a first cap (<NUM>) releasably engageable with the body (<NUM>) to selectively seal the collector port (<NUM>), the first cap (<NUM>) made from a non-magnetic material and defining a permanent magnet collector housing chamber (<NUM>) into which the permanent magnet collector (<NUM>) is removably locatable; characterised in that:
the strainer (<NUM>) further comprises a second cap (<NUM>) releasably engageable with the first cap (<NUM>) to selectively seal the permanent magnet collector housing chamber (<NUM>) and form a collector port cap assembly (<NUM>) that is releasably engageable with the body (<NUM>) of the strainer (<NUM>) by releasably engaging the first cap (<NUM>) to the body (<NUM>) to seal the collector port (<NUM>), the second cap (<NUM>) made from a non-magnetic material; and
said permanent magnet collector (<NUM>) is releasably securable to said second cap (<NUM>) to form a cap and magnet assembly (<NUM>) that is detachable from the first cap (<NUM>) while the first cap (<NUM>) is secured to the body (<NUM>) of the strainer.