Magnetic screen filter for central heating systems

Abstract

A filter of a combination of magnetic and non-magnetic (i.e. screen or gauze) for use in a central heating and / or cooling system. The filter has at least three ports and any of the multiple pairs of ports can be used as an inlet and outlet, providing a variety of mounting options to accommodate systems with different space constraints. The non-magnetic filter screen can be repositioned to be placed in the flow path associated with only one of the ports in the selected pair of ports.

Description

TECHNICAL FIELD

[0001] The present invention relates to a filter for a central heating system, in particular to a filter provided with a magnet for attracting and retaining magnetic particles, and a screen for retaining non-magnetic particles. BACKGROUND

[0002] It is well known to install a magnetic filter into a central heating system circuit. In a typical magnetic filter, a chamber is provided with an inlet and an outlet, and within the chamber a magnet is provided. System water flows into the inlet, through the chamber, and out of the outlet. Any magnetic particles in the fluid are captured by the magnet.

[0003] Some filters also include a screen or gauze. Water flows through the screen on its way from the inlet to the outlet, and any particles larger than the screen aperture are captured in the filter.

[0004] One problem with magnetic filters is that the space available for installing a filter around a boiler is often limited. In some installations, the pipework is buried in a wall, and only emerges from the wall a short distance below the boiler. GB2582028 describes a compact filter having four ports, any two of which can be selected for use. This design is to provide flexibility in installing the filter, particularly where there is only a short length of pipework below the boiler.

[0005] A filter sold under the trade mark Adey Magnaclean XS-90 has a similar four port configuration as shown in GB2582028, but has a fixed internal baffle instead of a moveable diverter.

[0006] However, the devices described in GB2582028 and Adey Magnaclean XS-90 are both purely magnetic filters. Neither provides filtration of non-magnetic particles. It is an object of the present invention to provide a magnetic and non-magnetic combined screen filter having similar installation flexibility. SUMMARY

[0007] According to the present invention, there is provided a magnetic and non-magnetic combined screen filter for a central heating or refrigeration system, the filter comprising:

[0008] a magnetic separation chamber containing a magnetic field;

[0009] an inlet / outlet assembly, the inlet / outlet assembly comprising at least three ports, any of a plurality of alternative pairs of ports being used as inlet and outlet ports to connect the magnetic separation chamber to a central heating or refrigeration system, unused ports of the at least three ports being closable, and the inlet / outlet assembly having a flow path between each port and the separation chamber; and

[0010] The non-magnetic screen filter assembly includes a screen for capturing particles,

[0011] The non-magnetic screen filter assembly is repositionable so as to selectively position the screen in the flow path of only one of the pair of ports for each of a plurality of selectable pairs of ports.

[0012] Three ports can be provided extending in different directions from the inlet / outlet assembly. For example, three ports can be provided all at right angles to each other. In some embodiments, four ports can be provided, with three at right angles to each other and the fourth co-linear with one of the other ports facing in the opposite direction. Five ports can also be provided, with four in the same plane facing in 0°, 90°, 180° and 270° directions and the fifth port extending at right angles to all of the first four. In other embodiments, even more ports can be provided allowing the ports to extend at angles other than multiples of 90° relative to each other.

[0013] The installer can select which two ports are most convenient to use as the inlet and outlet in a particular installation from the plurality of ports. In some embodiments, the installer can have complete flexibility in selecting which two of the plurality of ports Any Two, but it is envisaged that in some cases not every combination will work optimally. For example, in some embodiments, a particular port can only be suitable for use as an outlet and not as an inlet or can only be suitable for use in combination with some other ports.

[0014] When the installer selects a pair of ports for use as the inlet and outlet, the remaining ports will be closed. This can be achieved, for example, by simple screw caps. The screw caps close and seal the ports, preventing water passing through.

[0015] Once the pair of ports has been selected, the non-magnetic screen filter assembly is positioned so that the screen is in the flow path between one of the selected ports and the separation chamber but not in the flow path between the other of the selected ports and the separation chamber. Preferably, the screen is positioned in the flow path from the separation chamber to the outlet port. Thus, water will flow into the inlet and into the separation chamber without passing through the screen. Water from the separation chamber will pass through the screen on its way to the outlet. Any particles larger than the screen aperture and not captured by the magnets will be retained on the screen on the separation chamber side of the screen.

[0016] The inlet / outlet assembly preferably includes a flow guide, i.e. a structure that directs the flow and defines the flow path between each port and the separation chamber.

[0017] Preferably, the flow guide directs fluid such that the direction of flow into the separation chamber is substantially the same regardless of which port is used as an inlet. The flow paths into the chamber from each port can be substantially parallel to each other. Likewise, the direction of flow out of the separation chamber to the outlet is preferably substantially the same as the direction of any port used as an outlet. The outlet flow direction is substantially parallel but opposite in direction to the inlet flow direction. In many embodiments, most or all of the ports can be selected to be used as inlets or outlets.

[0018] The non-magnetic screen filter assembly can be substantially planar and can be positionable between the inlet / outlet assembly and the separation chamber. The non-magnetic screen filter assembly can be positionable at different locations in the same plane such that the screen is positioned in different flow paths depending on the location of the assembly. Preferably, the non-magnetic screen filter assembly can be repositioned by rotation (i.e. by placing the non-magnetic screen filter assembly in a new location which is a rotational transformation from the previous location; the actual motion required can not be simply rotation, for example removing the assembly and placing it back in the new location).

[0019] In some embodiments, the non-magnetic screen filter assembly comprises a frame which carries the screen. The non-magnetic screen filter assembly as a whole can be positionable in all flow paths corresponding to all ports, but in this case the screen does not extend over the entire non-magnetic screen filter assembly. The assembly can comprise apertures which, when positioned in a flow path, allow flow in that flow path to be substantially unrestricted, without passing through the screen.

[0020] The non-magnetic screen filter assembly can comprise a flow guide in the form of a sleeve. The sleeve of the non-magnetic screen filter assembly can be received within a wall of a flow guide of the inlet / outlet assembly and sealed against the wall. The sleeve can be part of a path through the non-magnetic screen filter assembly which does not pass through the screen. The sleeve can be received within any one of a plurality of flow guides in the inlet / outlet assembly and sealed against this flow guide. In this way, fluid is reliably directed from an inlet into the separation chamber without passing through the screen and then through the screen on its way out of the separation chamber. The sleeve sealing against the flow guide avoids any "leakage", i.e. allowing fluid to flow directly from an inlet to an outlet without passing through the separation chamber or the screen.

[0021] A sealing ring of compressible material can be provided on the sleeve for sealing against the flow guide of the inlet / outlet assembly.

[0022] In some embodiments, the non-magnetic screen filter assembly can be interchangeable with another non-magnetic screen filter assembly having a screen of a different grade. As an alternative, a single frame can be provided which can carry one of a plurality of screens of different grades.

[0023] Generally, smaller screen sizes will capture more particles. However, smaller screen sizes also lead to a static pressure drop across the filter. This pressure drop is undesirable because the heating system pumps will have to work harder and may fail prematurely if overloaded. Furthermore, the flow rate in the system may decrease to a degree that adversely affects performance; for example, all radiators in the system may take a long time to heat up when the system is turned on.

[0024] Therefore, a useful approach to using a filter is to use a fine screen when initially installing it and clean it periodically. This will essentially remove particles that would have accumulated in the system before the filter was installed. The fine screen can then be replaced with a coarser screen, which can remain in the system for a longer period between filter cleaning operations.

[0025] Furthermore, considering the pump's capacity, the particles present in the heating system water, and the potential problems caused by these particles, an appropriate screen size can be selected for a specific device. Choosing the right screen size may be a matter of weighing pros and cons, but interchangeable screens can facilitate this process.

[0026] In some embodiments, for devices requiring only magnetic filtration, the non-magnetic screen filter assembly may be fully removable. In certain cases, the screen may be used when the filter is initially installed and then removed for an extended period.

[0027] Preferably, the separation chamber is removable from the inlet / outlet assembly. This allows access to the non-magnetic screen filter assembly for repositioning. It also allows both the non-magnetic screen and the magnetic filter to be cleaned, although in some embodiments, filter cleaning can also be performed without disassembly by using a drain valve and flushing the filter. Attached Figure Description

[0028] To better understand the invention and to more clearly illustrate how to implement it, reference will now be made to the accompanying drawings by way of example only, wherein:

[0029] Figure 1 This is a perspective view of a boiler mounted on a wall;

[0030] Figure 2 This is a perspective view of the filter according to the present invention;

[0031] Figure 3 It shows Figure 2 The filter, which is installed with Figure 1 In the heating circuit adjacent to the boiler;

[0032] Figure 4 It shows Figure 2 The filter, which is optionally installed in conjunction with...Figure 1 adjacent to the heating circuit of the boiler of

[0033] Figure 5 is shown Figure 2 adjacent to the heating circuit of the boiler of Figure 1

[0034] Figure 6 is Figure 2 is a perspective view of the filter of

[0035] Figure 7 is an exploded view of the non-magnetic filter assembly that is part of the filter of Figure 2

[0036] Figure 8 is a perspective view of the inlet / outlet assembly that is part of the filter of Figure 2

[0037] Figure 9 is a perspective view of the separation chamber with the non-magnetic filter assembly installed, which is part of the filter of Figure 2 DETAILED DESCRIPTION

[0038] Referring first to Figure 1 , a boiler 100 is shown. The boiler 100 is wall-hung, which is typical for domestic or small commercial installations. Five pipes are shown extending from below the boiler. Since the pipes are buried in the wall of the building, only a short length is exposed. The pipes in a typical installation include for example gas (or other fuel) inlet, cold water inlet and hot water outlet (for a combination boiler), condensate drain (for a condensing boiler) and heating circuit flow and return. It is recommended that the heating circuit return flow point is the best point to install the filter, but for closed (pressurized) systems, installation on the flow circuit can also be chosen.

[0039] Figure 2 A filter 10 according to the present application is shown. The filter 20 includes a separation chamber 12, which is generally cylindrical, and an inlet / outlet assembly 14, which closes the cylinder and in this embodiment is provided with four ports. A first port 16, a second port 18, a third port 20 and a fourth port 22 are shown in the figure. The first port 16, the second port 18 and the third port 20 all extend away from the side of the cylinder in the same plane. The fourth port 22 extends from one end of the cylinder, perpendicular to all of the first port 16, the second port 18 and the third port 20.

[0040] ​​​​In some alternative embodiments, more or fewer ports can be provided. For example, one embodiment can omit the third port 20 and have only three ports 16, 18, 22, all of which are perpendicular to each other. Another embodiment can omit the second port 18 and have two ports 16, 20, which are in line with each other and face in opposite directions, and another port 22 which extends from the end of the cylinder. Yet another embodiment can have more ports, for example five ports. In addition to the fifth port which extends in the opposite direction to the port 18, all the ports 16, 18, 20, 22 as shown can be provided. Figure 2

[0041] All the ports are preferably provided with the same connection means, for example threads. Depending on the constraints of the particular installation, a pair of two ports are selected for use as inlet and outlet. In the example shown, the first port 16 and the second port 18 are selected for use as inlet and outlet. Pipe connections have been connected to these ports, one of which is provided with a valve. The third port 20 and the fourth port 22 are not used and a screw cap has been fitted over these ports to close and seal them. Figure 2

[0042] Figure 3 Figure 4 Figure 5 It is shown how different pairs of ports can be selected for use in order to provide flexibility in fitting the filter 10 for various different configurations, in particular for fitting into short pipe systems below a boiler 100.

[0043] Referring now to Figure 6 the internal components of the filter 10 can be seen. The magnet is fixed within the separation chamber 12 and is covered by a removable plastic sleeve 26. In use, fluid flows into the separation chamber 12 and any magnetic particles entrained in the fluid will be retained outside the plastic sleeve 26. When the filter 10 needs to be cleaned, after isolating and dismounting the filter, the plastic sleeve 26 can be removed from the magnet and cleaned, for example by running under a tap.

[0044] A drain valve 28 and a drain port 30 are provided in the separation chamber 12.

[0045] The separation chamber 12 is in the form of a generally cylindrical housing having an open end. The open end is closed by the inlet / outlet assembly 14 which is mounted on the open end of the separation chamber 12. Double O-ring seals are provided by a first O-ring 32 which is provided around the outside wall of the separation chamber 12, and a second O-ring 34 which abuts the end of the wall of the separation chamber 12. The cylindrical socket portion of the inlet / outlet assembly 14 receives the end of the substantially cylindrical housing of the separation chamber 12, with the first O-ring 32 located between the outer wall of the separation chamber 12 and the inner wall of the cylindrical socket portion of the inlet / outlet assembly 14. ​​​​

[0046] A flange 36 is provided on the separation chamber 12. A rotary locking ring 38 has internal threads that correspond to external threads provided on the outer wall of the cylindrical socket portion of the inlet / outlet assembly 14. When the threads of the locking ring 38 are engaged with the threads of the inlet / outlet assembly, the rotary locking ring 38 rests against the flange 36 of the separation chamber and serves to hold the separation chamber 12 on the inlet / outlet assembly 14.

[0047] A non-magnetic filter assembly 40 is provided in the form of a disc. The disc is removable and is mounted within the filter 10 between the separation chamber 12 and the inlet / outlet assembly 14. The non-magnetic filter assembly 40 comprises a screen portion 42 and an aperture 44. The non-magnetic filter assembly 40 is repositionable so that the aperture 44 is in the flow path associated with a selected one of the ports 16, 18, 20. Note that in this embodiment, the aperture 44 cannot be positioned in the flow path associated with the fourth port 22. Thus, the fourth port 22 should be used only as an outlet. However, it can be used in combination with any of the first, second and third ports 16, 18, 20.

[0048] In Figure 6 , the non-magnetic filter assembly 40 is positioned so that the aperture 44 is in the flow path associated with the third port 20. Thus, the third port is used as an inlet. With the non-magnetic filter assembly 40 in this position, any of the other ports can be used as an outlet. As shown, the first port 16 is used as an outlet and the port 22 is closed by a screw cap 46.

[0049] Figure 7 The non-magnetic filter assembly 40 is shown in more detail. The non-magnetic filter assembly is comprised of three parts - a carrier 48, a screen 50 and a screen retainer 52. Multiple grades of screen 50 can be provided so that an appropriate selection can be made for a particular installation. The screen 50 in use is provided on the screen portion 42 of the carrier 48 and is held in place by the retainer 52. The retainer 52 snaps onto the carrier 48 and is held in place, for example, by a resilient clip. The screen portion of the carrier 42 itself has a relatively coarse mesh, for example, with holes of about 3.5mm diameter. This can be used as the coarsest option, i.e. no separate mesh at all. Finer meshes are provided by inserting additional screen components 50.

[0050] Figure 8The inlet / outlet assembly 14 is shown. In particular, this view shows the flow guides in more detail. Each of the ports 16, 18, 20 has a respective flow guide 16a, 18a, 20a. The flow guides 16a, 18a, 20a form a right-angled passage between the respective port 16, 18, 20 and the end of the inlet / outlet assembly 14 which, in use, faces the separation chamber 12. The fourth port 22, which extends at right angles to all the other ports 16, 18, 20, does not have an associated flow guide, since the flow path between the fourth port 22 and the separation chamber 12 is simply the entirety of the interior of the inlet / outlet assembly which is not partitioned by the flow guides 16a, 18a, 20a.

[0051] Figure 9 The cylindrical housing of the separation chamber 12 is shown, with the non-magnetic filter assembly 40 mounted. From this view, it can be seen that the non-magnetic filter assembly 40 is mounted in the separation chamber 12 by means of a sleeve 54 which extends from the aperture 44 and into a selected one of the paths defined by the flow guides 16a, 18a, 20a. A seal ring 56 is provided to seal against the entrance to the respective flow path, ensuring that all fluid from the inlet passes through the aperture 44 into the separation chamber 12. Figure 8 and 9 From this view, it can be understood how the non-magnetic filter assembly 40 is arranged between the separation chamber 12 and the inlet / outlet assembly. In particular, the sleeve 54 extends from the aperture 44 and into a selected one of the paths defined by the flow guides 16a, 18a, 20a. A seal ring 56 is provided to seal against the entrance to the respective flow path, ensuring that all fluid from the inlet passes through the aperture 44 into the separation chamber 12.

[0052] The filter of the present invention provides a combination of magnetic and non-magnetic (sieve) filtration, which can be installed in a variety of different configurations depending on the requirements of the particular system. Furthermore, the interchangeable / removable sieve means that the appropriate sieve size can be selected to provide the required level of particle capture, whilst maintaining a reasonable maintenance interval and not overloading the system pump.

[0053] The above-described embodiments are provided as examples only and various changes and modifications can be made to the present invention without departing from the scope of the invention as defined in the appended claims.

Claims

1. A magnetic and non-magnetic combined screen filter for centralized heating and / or cooling systems, said filter comprising: Magnetic separation chamber, containing a magnetic field; An inlet / outlet assembly comprising at least three ports, any one of a plurality of optional port pairs serving as an inlet and an outlet port for connecting the magnetic separation chamber to a central heating or cooling system, wherein unused ports of the at least three ports are closable, and the inlet / outlet assembly has a flow path between each port and the magnetic separation chamber; and A non-magnetic screen filter assembly, the non-magnetic screen filter assembly including a screen for capturing particles, The non-magnetic screen filter assembly is repositionable to selectively position the screen for each of the plurality of optional port pairs, thereby positioning the screen in the flow path of only one port of the port pair. The non-magnetic screen filter assembly is flat and can be repositioned to different locations within the same plane.

2. The filter of claim 1, wherein the inlet / outlet assembly is provided with three ports facing different directions.

3. The filter as claimed in claim 2, wherein the three ports are perpendicular to each other.

4. The filter as claimed in any one of claims 1-3, wherein at least four ports are provided.

5. The filter of claim 4, wherein three ports are perpendicular to each other, and a fourth port is collinear with one of the other ports and faces the opposite direction.

6. The filter of claim 1, wherein a cap is provided for closing unused ports.

7. The filter of claim 1, wherein the inlet / outlet assembly includes a flow deflector that defines a flow path between each port and the magnetic separation chamber.

8. The filter of claim 1, wherein the non-magnetic screen filter assembly includes pores that are selectively positioned in one of the flow paths to allow unrestricted flow in the flow paths.

9. The filter of claim 8, wherein the nonmagnetic screen filter assembly includes a sleeve for guiding fluid from a selected flow path in the inlet / outlet assembly through the orifices in the nonmagnetic screen filter assembly.

10. The filter of claim 1, wherein the screen is removable and can be replaced by screens of different grades.

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