GB2602986A

GB2602986A - Magnetic and mesh filter for a central heating system

Info

Publication number: GB2602986A
Application number: GB2100861.0A
Authority: GB
Inventors: Button Mark; Ferry Alan; Clough Rob
Original assignee: Adey Holdings 2008 Ltd
Current assignee: Adey Holdings 2008 Ltd
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2022-07-27
Anticipated expiration: 2041-01-22
Also published as: GB2602986B; CN114870486A; CN217247333U; GB202100861D0

Abstract

A combined magnetic and non-magnetic (i.e. mesh / gauze) filter 40 is provided for use with a central heating and / or cooling system. The filter has at least three ports 16,18,20, and any of a plurality of pairs of ports may be selected for use as the inlet and outlet, to provide for multiple installation options to suit systems with different space constraints. The non-magnetic filter mesh is repositionable to be placed in a flow path associated with only one of the ports of the selected pair of ports. Optionally caps 46 may be provided for unused ports and flow guides can define flow paths between each port and the separation chamber.

Description

MAGNETIC AND MESH FILTER FOR A CENTRAL HEATING SYSTEM

The present invention relates to a filter for a central heating system, in particular a filter provided with a magnet for attracting and retaining magnetic particles, as well as a mesh for retaining non-magnetic particles.

BACKGROUND TO THE INVENTION

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 a magnet within the chamber. System water flows into the inlet, through the chamber, and out of the outlet. Any magnetic particles in the flow are captured by the magnet.

Some filters additionally include a mesh or gauze. Water flows through the mesh on its way from the inlet to the outlet, and any particles larger than the size of the apertures in the mesh will be captured in the filter.

One problem with magnetic filters is that there is often limited space surrounding a boiler in which to fit a filter. In some installations, pipes are buried in the walls and emerge from the walls only a short distance below the boiler. GB2582028 describes a compact filter with four ports, any two of which may be selected for use. This is designed to provide flexibility in fitting the filter, especially in small spaces and where there is only a short length of pipe underneath a boiler.

A filter sold under the trade mark Adey MagnaClean XS-90 has a similar configuration of four ports as is shown in GB2582028, but has fixed internal flow guides rather than a movable flow diverter.

However, both the device described in GB2582028 and the Adey MagnaClean XS-90 are magnetic-only filters. Neither provide for filtration of non-magnetic particles. It is an object of the present invention to provide a combined magnetic and non-magnetic filter, with similar flexibility for installation.

STATEMENT OF INVENTION

According to the present invention, there is provided a combined magnetic and nonmagnetic filter for a central heating or cooling system, the filter comprising: a magnetic separation chamber containing a magnetic field; an inlet / outlet assembly, the inlet / outlet assembly comprising at least three ports, any of a plurality of alternative pairs of ports being selectable for use as inlet and outlet ports for connecting the magnetic separation chamber into the central heating or cooling system, unused ports of the at least three ports being closable, and the inlet! outlet assembly having flow paths between each port and the separation chamber; a non-magnetic filter assembly, the non-magnetic filter assembly comprising a mesh for capturing particles, the non-magnetic filter assembly being repositionable, for selectively positioning the mesh to be disposed in the flow path of only one port of the pair of ports, for each of the plurality of alternative pairs of ports.

Three ports may be provided, all extending from the inlet! outlet assembly in different directions. For example, three ports may be provided all at right angles to each other. In some embodiments, four ports could be provided -three of them at right angles to each other and a fourth port which is in-line with, facing in the opposite direction to, one of the other ports. Five ports could also be provided -four of them in the same plane and facing in 0°, 90°, 180° and 270° directions, and a fifth port extending at right angles to all of the first four ports. In other embodiments, even more ports could be provided, allowing for ports extending at angles other than multiples of 90° with respect to each other.

An installer may choose from the plurality of ports which two of the ports are most convenient for use as the inlet and outlet in a particular installation. In some embodiments, the installer may have full flexibility to choose any two of the plurality of ports, but it is envisaged that in some cases not every combination will work optimally. For example, in some embodiments a particular port may only be suitable for use as an outlet and not as an inlet, or may only be suitable for use in combination with some of the other ports.

VVhen the installer has chosen a pair of ports to use as the inlet and outlet, the remaining ports will be closed. This may be done for example by a simple screw-on cap, which closes and seals the port, preventing water from passing through.

Once the pair of ports is chosen, the non-magnetic filter assembly is positioned so that the mesh is in the flow path between one of the chosen ports and the separation chamber, but is not in the flow path between the other of the chosen ports and the separation chamber. Preferably, the mesh is positioned in the flow path from the separation chamber to the outlet port. Hence, water will flow into the inlet, and into the separation chamber without flowing through the mesh. From the separation chamber the water will pass through the mesh on its way to the outlet. Any particles which are larger than the holes in the mesh, and which have not been captured by the magnet, will be retained on the mesh on the separation chamber side of the mesh.

The inlet! outlet assembly preferably includes flow guides, i.e. formations which guide flow and define the flow paths between each port and the separation chamber.

Preferably the flow guides guide flow such that the flow direction upon entry to the separation chamber is in substantially the same direction, whichever port is used as the inlet. The flow paths from each port, into the chamber, may be substantially parallel to each other. Likewise, the flow direction upon exit from the separation chamber, to the outlet, is preferably in substantially the same direction whichever port is used as the outlet. The exit flow direction is substantially parallel with but in the opposite direction to the entry flow direction. In many embodiments, most or all of the ports can be selected for use as either inlet or outlet.

The non-magnetic filter assembly may be substantially planar, and be positionable between the inlet/outlet assembly and the separation chamber. The non-magnetic filter assembly may be positionable in different positions in the same plane so that the mesh is positioned in different flow paths, depending on the position of the assembly.

Preferably, the non-magnetic filter assembly is repositionable by rotation (i.e. by putting the non-magnetic filter assembly in a new position which is a rotational transformation compared with the previous position; the actual motion required may be more than rotation, for example removing the assembly and replacing it in a new position).

In some embodiments, the non-magnetic filter assembly includes a framework which carries the mesh. The non-magnetic filter assembly as a whole may be positioned in all flow paths corresponding with all ports, but in that case the mesh does not extend over the whole of the non-magnetic filter assembly. The assembly may comprise an aperture which when positioned in a flow path, allows substantially unrestricted flow in that flow path, without the flow passing through the mesh.

The non-magnetic filter assembly may include a flow guide in the form of a spigot. The spigot of the non-magnetic filter assembly may be received within, and seal against, the walls of a flow guide of the inlet! outlet assembly. The spigot may be part of the path through the non-magnetic filter assembly which does not pass through the mesh.

The spigot may be received within and seal against any one of a plurality of flow guides in the inlet! outlet assembly. In this way, flow is guided reliably from the inlet into the separation chamber without passing through the mesh, and then passes through the mesh on its way out of the separation chamber. The spigot sealing against the flow guide avoids any 'leakage', i.e. fluid being allowed to flow directly from the inlet to the outlet, without passing through the separation chamber or the mesh.

A sealing ring made from a compressible material may be provided on the spigot for sealing against the flow guide of the inlet / outlet assembly.

In some embodiments, the non-magnetic filter assembly may be interchangeable with another non-magnetic filter assembly having a different grade of mesh. As an alternative, a single framework may be provided which can carry one of a plurality of different grades of mesh.

In general a smaller mesh size will trap more particles. However, a smaller mesh size will also cause a static pressure drop across the filter. Pressure drop is undesirable since the heating system pump will have to work harder, and may fail prematurely if overloaded. Also, the flow rate in the system may be reduced to the extent that performance is adversely affected, for example, it will take too long for all radiators in the system to heat up when the system is switched on.

One useful way of using the filter therefore is to use a fine mesh when the filter is first installed, and to clean the mesh regularly for a period of time. This should substantially clean particles from the system which have built up while no filter was installed. The fine mesh can then be changed for a coarser mesh, which can be left in place in the system for much longer periods of time between filter cleaning operations.

Also, a suitable mesh size can be chosen for a particular installation bearing in mind the capability of the pump, and the particles which are present in the heating system water and the potential for problems to be caused by those particles. The choice of mesh size may be a matter of weighing up trade-offs, but an interchangeable mesh allows that to be done.

The non-magnetic filter assembly in some embodiments may be completely removable, for installations where only magnetic filtration needs to be provided. In some case, a mesh could be used when the filter is first installed, and then removed for the longer term.

Preferably, the separation chamber is detachable from the inlet / outlet assembly. This allows access to the non-magnetic filter assembly, for repositioning. This also allows both the non-magnetic and magnetic filters to be cleaned, although in some embodiments cleaning the filter may also be possible without disassembly, by using a drain valve and flushing the filter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which: Figure 1 is a perspective view of a boiler installed on a wall; Figure 2 is a perspective view of a filter according to the invention; Figure 3 shows the filter of Figure 2, installed in a heating circuit adjacent the boiler of Figure 1 Figure 4 shows the filter of Figure 2, installed in a heating circuit adjacent the boiler of Figure 1, in an alternative configuration; Figure 5 shows the filter of Figure 2, installed in a heating circuit adjacent the boiler of Figure 1, in a further alternative configuration Figure 6 is a perspective view of the filter of Figure 2, with parts cut away so that the internals are visible; Figure 7 is an exploded view of a non-magnetic filter assembly, part of the filter of Figure 2; Figure 8 is a perspective view of an inlet! outlet assembly, part of the filter of Figure 2; and Figure 9 is a perspective view of a separation chamber with a non-magnetic filter assembly fitted, part of the filter of Figure 2.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring firstly to Figure 1, a boiler 100 is shown. The boiler 100 is wall-mounted, as is typical for a domestic or small commercial installation. Five pipes are shown extending from below the boiler. The pipes are only exposed for a short length, as they are buried in the wall of the building. The pipes in a typical installation include for example gas (or other fuel) in, cold water in and hot water out (for a combination boiler), condensate drain (for a condensing boiler) and heating circuit flow and return. The heating circuit return is recommended as the best point to fit a filter, although installation on the flow is also an option for closed (pressurized) systems.

Figure 2 shows a filter 10 according to the invention. The filter 20 includes a separation chamber 12 which is roughly cylindrical, and an inlet! outlet assembly 14 which closes the cylinder and provides, in this embodiment, four ports. A first port 16, second port 18, third port 20 and fourth port 22 are indicated in the drawing. The first, second and third ports 16, 18,20 extend away from sides of the cylinder, all in the same plane. The fourth port 22 extends from an end of the cylinder, perpendicular to all of the first second and third ports 16, 18, 20.

In some alternative embodiments, more ports or fewer ports may be provided. For example one embodiment could omit the third port 20, and have just three ports 16, 18, 22 which are all mutually perpendicular. Another embodiment could omit the second port 18, and have two ports 16, 20 in-line with each other and facing in opposite directions, and another port 22 extending from the end of the cylinder. Yet another embodiment could have more ports, for example five ports. All the ports 16, 18, 20, 22 as shown in Figure 2 could be provided, in addition to a fifth port extending in the opposite direction to port 18.

All of the ports are preferably provided with identical connection means, for example screw threads. A pair of two ports are chosen for use as the inlet and outlet, according to the constraints of the particular installation. In the example shown in Figure 2, the first port 16 and second port 18 have been chosen for use as the inlet and outlet. Pipe connections have been attached to these ports, one of which is provided with a valve. The third point 20 and fourth port 22 are not in use and screw caps have been fitted over these ports, to close and seal them.

Figures 3, 4 and 5 illustrate how different pairs of ports can be chosen for use, in order to provide flexibility to fit a filter 10 in various different configurations, especially to a short length of pipework underneath a boiler 100.

Referring now to Figure 6, the internal components of the filter 10 are visible. A magnet is fixed inside 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 on the outside of the plastic sleeve 26. Vilhen the filter 10 needs to be cleaned, after isolating and disassembling the filter, the plastic sleeve 26 can be removed from the magnet and cleaned, for example by running under a tap.

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

The separation chamber 12 is in the form of a roughly cylindrical shell with an open end. The open end is closed by an inlet! outlet assembly 14, which fits over the open end of the separation chamber 12. A double 0-ring seal is provided by a first 0-ring 32 provided around an outer side wall of the separation chamber 12, and a second 0-ring 34 against an end of the wall of the separation chamber 12. A cylindrical socket portion of the inlet! outlet assembly 14 receives an end portion of the substantially cylindrical shell of the separation chamber 12, the first 0-ring 32 being located between an outer wall of the separation chamber 12 and an inner wall of the cylindrical socket portion of the inlet! outlet assembly 14.

A flange 36 is provided on the separation chamber 12. A rotating locking ring 38 has an internal screw thread corresponding with an external screw thread provided on the outside wall of the cylindrical socket portion of the inlet / outlet assembly 14. The rotating locking ring 38 bears against the flange 36 of the separation chamber, and serves to retain the separation chamber 12 to the inlet! outlet assembly 14, when the thread of the locking ring 38 is engaged with the thread of the inlet! outlet assembly.

A non-magnetic filter assembly 40 is provided in the form of a disc. The disc is removable, and fits within the filter 10 between the separation chamber 12 and the inlet / outlet assembly 14. The non-magnetic filter assembly 40 includes a mesh 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 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. Therefore the fourth port 22 should only be used as an outlet. However, it may be used in combination with any of the first second and third ports 16, 18, 20 In Figure 6, the non-magnetic filter assembly 40 is positioned with the aperture 44 in the flow path associated with the third port 20. The third port is therefore being used as the inlet. Any of the other ports could be used as the outlet with the non-magnetic filter assembly 40 in this position. As shown in the drawing, the first port 16 is being used as the outlet, and port 22 is seen closed with a screw cap 46.

Figure 7 shows the non-magnetic filter assembly 40 in more detail. The non-magnetic filter assembly is made from three parts -a carrier 48, a mesh 50 and a mesh retainer 52. Multiple grades of mesh 50 may be provided so that an appropriate choice may be made for a particular installation. The mesh 50 in use is disposed over the mesh portion 42 of the carrier 48, and held in place by the retainer 52. The retainer 52 snaps onto the carrier 48 and remains attached for example by resilient clips. The mesh portion of the carrier 42 has a relatively coarse grid of its own, for example with apertures of around 3.5mm diameter. This may be used as the most coarse option, i.e. without a separate mesh at all. Finer meshes are provided by insertion of an additional mesh component 50.

Figure 8 shows the inlet / outlet assembly 14. 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 faces into the separation chamber (12) in use. 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 all the parts inside the inlet! outlet assembly which are not partitioned off by flow guides 16a, 18a, 20a.

Figure 9 shows the cylindrical shell of the separation chamber 12, with the nonmagnetic filter assembly 40 fitted. From figures 8 and 9 it will be understood how the non-magnetic filter assembly 40 is disposed between the separation chamber 12 and the inlet! outlet assembly. In particular, a spigot 54 extends from the aperture 44 and extends into a selected one of the paths defined by flow guides 16a, 18a, 20a. A sealing ring 56 is provided to seal against the entrance to the respective flow path, ensuring all flow from the inlet passes through aperture 44 into the separation chamber 12.

The filter of the invention provides for a combination magnetic and non-magnetic (mesh) filter which can be installed in a variety of different configurations, depending on the requirements of a particular system. In addition, the interchangeably / removable mesh means that an appropriate mesh size can be chosen to provide the required level of particle capture, while maintaining a reasonable service interval and not overloading a system pump.

The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.

Claims

CLAIMS1. A combined magnetic and non-magnetic filter for a central heating and/or cooling system, the filter comprising: a magnetic separation chamber containing a magnetic field; an inlet! outlet assembly, the inlet / outlet assembly comprising at least three ports, any of a plurality of alternative pairs of ports being selectable for use as inlet and outlet ports for connecting the magnetic separation chamber into the central heating or cooling system, unused ports of the at least three ports being closable, and the inlet / outlet assembly having flow paths between each port and the separation chamber; a non-magnetic filter assembly, the non-magnetic filter assembly comprising a mesh for capturing particles, the non-magnetic filter assembly being repositionable, for selectively positioning the mesh to be disposed in the flow path of only one port of the pair of ports, for each of the plurality of alternative pairs of ports.
2. A filter as claimed in claim 1, in which three ports of the inlet! outlet assembly are provided, all facing in different directions.
3. A filter as claimed in claim 2, in which the three ports are mutually perpendicular to each other.
4. A filter as claimed in any of the preceding claims, in which at least four ports are provided.
5. A filter as claimed in claim 4, in which three of the ports are mutually perpendicular to each other and the fourth port is in-line with, facing in the opposite direction to, one of the other ports.
6. A filter as claimed in any of the preceding claims, in which caps are provided for closing unused ports.
7. A filter as claimed in any of the preceding claims, in which the inlet! outlet assembly includes flow guides which define the flow paths between each port and the separation chamber.
8. A filter as claimed in any of the preceding claims, in which the non-magnetic filter assembly is substantially planar.
9. A filter as claimed in claim 8, in which the non-magnetic filter assembly is reposifionable in different positions in the same plane.
10. A filter as claimed in any of the preceding claims, in which the non-magnetic filter assembly comprises an aperture which is selectively positionable in one of the flow paths, allowing unrestricted flow in that flow path.
11.A filter as claimed in claim 10, in which the non-magnetic filter assembly includes a flow guide for guiding flow from a selected flow path in the inlet / outlet assembly, through the aperture in the non-magnetic filter assembly.
12. A filter as claimed in any of the preceding claims, in which the mesh is removable and replaceable with a different grade of mesh.