GB2433101A

GB2433101A - Manifold for central heating boiler

Info

Publication number: GB2433101A
Application number: GB0624676A
Authority: GB
Inventors: Soeren Stig Abildgaard
Original assignee: EC Power AS Norway
Current assignee: EC Power AS Norway
Priority date: 2005-12-09
Filing date: 2006-12-11
Publication date: 2007-06-13
Anticipated expiration: 2026-12-11
Also published as: GB0525157D0; GB0624676D0; GB0723534D0; GB2433101B; CN101326405A; RU2008122894A; RU2431782C2; WO2007066135A2; JP2009518616A; WO2007066135A8; WO2007066135A3; EP1957877A2

Abstract

A fluid manifold (distributor) 10 for interconnecting fluid components in a central heating system e.g. within a boiler or CHP system, comprises at least one inlet port and at least one outlet port 13, 14 which are joined by one or more passageways. The passageways are formed of a series of chambers 25b, 27b, enclosed by an outer casing formed by an outer wall 11, 12, and the outer wall forms part of a wall of at least one of the chambers. The manifold is compact and allows a space saving compared with conventional piping.

Description

24331O1

FLUID DISTRIBUTOR

The present invention relates to a fluid distributor and more particularly, but not exclusively, to a distributor of the type used as part of an industrial or domestic central heating arrangement.

In a domestic or industrial central heating arrangement or installation, the components of the system i.e. the heat source, pumps, heat exchangers and the like, are fluidly connected together by means of pipes or conduits. The pipes are generally arranged to communicate hot or cold water between the components of the system such as from a heat source, via pumps, to one or a series of radiators.

In conventional arrangements these components are connected by a series of pipes which have been pre-formed, or bent, into the required geometry. The pipes are generally formed using specialist equipment so as to fluidly connect the various components together and to provide the required flowpath(s) between components.

In these conventional arrangements the space required between the components of the heating system can be considerable as a result of the limit of radius of curvature which can be achieved for a given pipe diameter. This is particularly the case for pipes of large diameter (which are often used for higher pressure industrial applications) where curves having a small radius cannot be achieved. This results in larger distances between components than would normally be required or desired and leads to large installations in which the components of the installation are undesirably spaced apart. Furthermore, arrangements where large numbers of pipes are used having complex interconnections are labour intensive to form and to install and are frequently prone to leaks, particularly around joints or bends in the pipe work.

An example of an arrangement in which a complex pipe network is used to interconnect components is shown in Figure IA.

In many applications it is in fact essential that the amount of space used is minimal and that the components (e.g. pumps, valves and the like) are situated as close together as possible. This is particularly the case in applications where an installation is required to be contained within a defined space or in a casing such as a combined heat and power unit (CHP).

Typical CHP systems generally comprise a motor/generator set, a heat storage unit, a boiler and a heat pump which are required to consume as small a space as

I

possible. Preferably, the heat (and electrical) source, together with the heat exchangers, pumps, valves and associated interconnections are all contained within a single casing and it is desirable to minimise the size of the casing and thereby the overall space which the unit consumes.

S One means to minimise the space consumed by the connections between components within such an installation is to use a manifold or distributor arrangement. A manifold can be used as a common conduit to which a number of components can be connected, thereby allowing fluid to flow between inlet and outlet ports along the manifold and between respective components. This does not however provide for specific flow paths between components.

Viewed from a first aspect, there is provided a distributor for distributing water in a central heating system, comprising at least one inlet port and at least one outlet port and one or more passageways defined therebetween, wherein the passageway(s) is/are formed of a series of chambers enclosed by an outer casing formed by an outer wall, wherein the outer wall forms part of a wall of at least one of the chambers.

With this arrangement, the distributor is formed as a contained unit without the need for complex arrangements of pipes or manifolds.

The outer wall may form a pressure chamber to contain the pressure within the distributor. Chamber walls may be provided within the outer wall to divide the space enclosed by the outer wall into the chambers. With this arrangement the chamber walls and other internal components do not need to be particularly strong, as the pressure differential between adjacent chambers will be substantially less than the differential between the outside and the inside of the distributor. This is particularly the case when the distributor is used in a system such as a central heating system where water is maintained at a substantially constant pressure, as the pressure differential between adjacent chambers will then be very small or there may in fact be no pressure differential.

Preferably the two chambers are an outer chamber and an inner chamber. The outer wall may be with a major part of the outer wall forming a part of the wall enclosing the outer chamber, and the remainder of the outer wall forming a part of the wall enclosing the inner chamber.

The series of chambers disposed between the inlet and outlet ports define one or more passageways, or paths, through which water can be communicated.

The outer wall is preferably arranged to withstand a pressure of up to 3 bar, more preferably up to 10 bar and most preferably up to 15 bar. The chamber walls and partition members i.e. those members defining the inner chambers and sections, are preferably selected to withstand a pressure of up to 0.1 bar, more preferably 0.5 bar and most preferably I bar. These pressures represent the pressure differentials across the walls of the outer wall and inner chamber walls.

Although the distributor is for distribution of water in a central heating network it will be appreciated that it will find use in distributing other fluids in different types of network. Preferably the distributor distributes fluid between various fluid components. The term fluid components' is intended to refer to any suitable component of a fluid handling system, particularly components of the type used in a central heating system. Such components include, but are not limited to, pumps, valves, heat exchangers, radiators and so forth, as well as pipes or conduits providing a connection to such components and other components.

In a preferred embodiment the distributor comprises an outer wall in the form of a prism, for example an elongate rectangle, a tube or a semi-circular prism.

This embodiment can readily be manufactured to handle higher pressures and higher flow rates when compared to the previous embodiment, because the presence of large separation forces are avoided, and instead the pressure within the distributor is contained by tensile stresses in the outer wall.

With this arrangement, where the pressure throughout the system to which the distributor is connected is substantially constant (such as in a central heating system), the pressure difference between chambers within the distributor can be minimised.

Thus, the wall thickness and thereby the size and complexity of the internal components forming the chambers of the distributor can be minimised.

It will be recognised that, as discussed above, in such an arrangement the only significant pressure differential which must be accommodated is defined by the difference between the internal pressure of the system (which is preferably substantially common to all chambers) and the pressure surrounding the distributor.

Thus, the inner chambers can be provided with a substantially thin wall section and the outer wall can be provided with a wall thickness or geometry sufficient to accommodate this pressure.

The outer wall may comprise two sections, for example U-shaped or semi-circular sections, which are placed facing each other to define a space for chambers between them. The chambers may then be formed by one or more partition members within the outer wall. In one preferred embodiment the distributor comprises a partition member with two sections of the outer wall placed either side of the partition member.

Alternatively the distributor may be built up from a number of sections either placed face to face or stacked together, with the outer wall then being formed by the exposed outer faces of the sections, and the chambers being formed by the areas enclosed by the sections. th one preferred embodiment the sections have a square gutter or U-shaped cross-section and are stacked forming a ladder shape in cross-section. Partitions forming further chambers may be added.

Preferably however, the outer wall is formed as a hollow prism, with the chamber walls being placed within the outer wall to divide the space enclosed by the outer wall into chambers. This allows a strong outer wall to be formed as there are no joints about the outer wall that would otherwise provide weak points.

Thus, generally the distributor comprises an outer wall that encircles a number of chamber walls, the chambers being formed by the spaces between the walls.

Preferably the distributor is elongate and is divided along its length into number of chambers. These chambers may then be further divided by cross plates or partitions placed across the width of one or more chambers.

The distributor is preferably provided with a plurality of inlet and outlet ports arranged to communicate water into and out of the distributor. The passageways may be arranged to communicate water between particular inlet and outlet ports and/or may be arranged, by means of a valve or valves (or other suitable means), to selectively direct water to particular outlets from a particular inlet or inlets. Valves may be placed to direct water between chambers or between a chamber and an inlet or outlet.

The distributor may be formed of an outer wall defining an (outer) chamber which is arranged to surround all of the remaining (inner) chamber(s) and is furthermore arranged to accommodate the pressure of the system to which the distributor is to be connected.

In an application where the water passing through the distributor is at a relatively low pressure, for example between I and 6 bar, the outer wall may be formed of a generally square or rectangular cross-section thereby facilitating convenient manufacture. The cross-section need not be a perfect square or rectangle with right-angled corners, and in particular curved corners are preferably used to reduce stress concentrations and hence increase the pressure which can be used.

In an application where the water passing through the distributor is at a relatively high pressure, for example in excess of 6 bar, the outer wall may be formed of a circular or part-circular profile so as to minimise the wall thickness required to accommodate the pressure of the system.

In another preferred embodiment the outer wall is formed of a first substantially flat portion arranged to receive the inlet and outlet ports and a second portion being partially circular or curved in section and arranged to accommodate the pressure. The first and second portions may be connected together and sealed to provide the outer chamber.

The second portion of the outer wall may be formed of any suitable profile which minimises the material which is required to accommodate the internal pressure of the system. The second portion may for example be formed of an elongate length of material folded into a U'-shape cross-section to which the substantially flat first portion can be connected to provide a D'-shaped cross-section. Alternatively, the second portion may be an elongate extrusion having a U' shape or semi-circular shape, again to which the substantially flat front portion can be connected. The ends of the outer wall may be sealed by end plates as discussed below or in any other convenient manner.

It will be recognised that the thickness of material selected for the construction of the outer wall and inner partitioning members or chamber walls of a distributor described herein is dependent on the pressure requirements of the given installation.

For example, in a typical domestic central heating arrangement where the outer wall is formed using a steel, the first portion may have a wall thickness of between 2 and 10 mm. Similarly, the second portion may have a wall thickness of between 0.5 mm and 2.5 mm. Alternatively, in an arrangement where the outer wall is formed using aluminium, the first portion may have a wall thickness of between 5 mm and 15 mm. Similarly the second portion may have a wall thickness of between 1.5 mm and 2.5 mm. In higher pressure applications, such as industrial applications larger wall thickness values may be required.

Thus, there is provided an outer sealed chamber having inlet and outlet ports arranged to allow water flow into and out of the distributor. The inlet and outlet ports are arranged so as to be in fluid communication with respective chambers within the outer wall.

In an alternative outer wall arrangement, for example an outer wall having a rectangular or box like cross-section, the inlet and outlet ports may be arranged on any suitable face of the outer wall.

The distributor parts may be formed of any suitable material capable of being formed into the necessary shape and capable of accommodating the necessary pressures and/or temperatures. The distributor may for example be formed of a single material or may be constructed of different materials for different components. For example, the outer wall may be formed of a higher strength material than the inner components forming the inner chamber walls. Suitable materials include, but are not limited to, steel, aluminium or thermosetting plastics. In situations where materials are used which are susceptible to corrosion, suitable corrosion protection is also preferably provided.

The outer wall is preferably arranged to surround the inner chambers and to act, as described above, as a pressure vessel. It will be recognised that the inner chambers may be completely surrounded by an outer chamber but are preferably partly surrounded by the outer chamber such that one face of each inner chamber can be conveniently fluidly connected to adjacent inner members (as described below) and to the inlet and or outlet ports of the distributor. Thus, the inner members forming the inner chamber walls may be stacked against an internal surface of the outer wall or against the inner surface of the substantially flat portion of the outer wall. This facilitates convenient construction of the inner chambers and fluid connection of the inner members (and thereby the inner chambers) to the inlet and outlet ports.

The inner member(s) are preferably formed of elongate members extending along at least part of the length of the distributor and having a generally wide and thin profile so as to minimise the overall depth of the distributor. The depth of these preferred features of the distributor is intended to refer to the distance from the front substantially flat portion of the outer wall to the to the rear face of the outer wall. It will be appreciated that the size of the outer wall is defined by the total depth of the inner members forming the inner chambers and the required size of the outer chamber surrounding the inner chambers, combined with the wall thickness of the outer wall.

The inner members are preferably positioned adjacent and on top of one another within the outer wall so as to minimise the thickness of the distributor.

The parts forming the passageways and inner chamber walls may be formed of generally U-shaped elongate members which, when stacked upon one another, define series of substantially parallel chambers between each of the members.

It will be appreciated that the cross-section of the inner members may be any suitable profile which, in use, define passageways along which a fluid can be communicated. The inner members may for example be extruded semi-circular members which, when similarly stacked upon one another, define passageways therebetween.

The elongate chambers formed by stacking the elongate inner members are preferably divided using suitable cross plates placed across the width of the chambers so as to provide a number of chambers along the length of the elongate inner member.

This thereby increases the number of flow paths which can be provided. The cross plates are preferably elements having cross-sectional profiles arranged to seal-off portions of the inner members.

In a preferred embodiment, cross plates are inserted into slots in the outer wall in order to divide the chambers. The cross plates may form a wall across the entire cross-section of the distributor, or they may be arranged to form a wall across the width of only some of the chambers. The ends of the distributor may be sealed using cross plates.

The slots in the distributor preferably comprise slots cut from two faces of the distributor, leaving tabs forming connecting portions between the two slots which join the two lengths of the distributor divided by the slots. The cross plates may have recesses to accommodate the tabs. Preferably the recesses are sized to closely fit around the tabs.. The cross plate may have a hole at one end that opens onto the recess, the hole being arranged such that the cross plate can be placed partially in the slot with a tab in the hole, and rotated about the tab into the slot. With this arrangement once the cross plate is rotated into the slot it can then be slid across to engage the tabs in the recesses. A plug may be provided to fit into the hole.

Alternatively, the hole may form a flow path between two chambers either side of the cross plate.

The cross-sectional area of each flow path in the distributor is preferably selected in accordance with the required fluid flow rate through the particular flow path of the distributor. Most preferably the cross-sectional area is at least comparable to the inlet and outlet port areas to which a particular flow path is connected. Thus, the distributor does not unduly limit the fluid flow between fluid components.

The inner members are preferably connected together (in combination with suitable partitions) such that each chamber is sealed from an adjacent chamber, other than via a aperture or apertures which are arranged to provide the flow path. The inner members may be connected together using any suitable means given the type of material from which the inner members are formed. The inner members may for example be joined by means of welding, brazing or an adhesive bond.

Preferably, to construct the distributor, the inner members are first brought into close contact with one another so as to minimise the welding or bonding required.

The inner members may further be provided with suitable recesses and protrusions so as to allow adjacent members to be conveniently positioned and connected.

Each of the chambers is preferably provided with an aperture or apertures fluidly connecting respective chambers together so as to provide the required flow path(s). One or more of the chambers is/are preferably provided with an aperture or apertures which are directly fluidly connected to the inlet andlor outlet ports arranged in the outer wall. Thus, a flow path or paths can be defined from an inlet port into a first chamber and through a series of further chambers to one or more outlet ports.

Alternatively, a flow path may be provided via a single chamber i.e. via an inlet port fluidly communicating with a chamber to an outlet port, fluidly communicating with the same chamber.

Thus, any required flow path through the distributor can be provided by suitably connecting inlet ports and outlet ports to respective chambers having suitably arranged apertures therebetween. It will be appreciated that any combination of chambers, partitions and apertures may be used to define a flow path or paths between the inlet port(s) and outlet port(s) within the distributor.

The distributor may further be provided with insulation to prevent or limit heat loss from the water within the distributor. The insulation may for example be in the form of a casing surrounding the outer wall of the distributor and containing an insulating medium such as a foam for example. Alternatively, the outer wall may be provided with an insulating layer arranged to surround and to contact the wall. This may for example be in the form of an insulating jacket.

A distributor according to an invention described herein provides a convenient and compact means to interconnect fluid components of a system such as a central heating system in a minimal space. Furthermore, a distributor according to an invention disclosed herein provides a means to interconnect fluid components operating at elevated pressures which can be substantially constructed from sheet or thin walled materials thereby making manufacture simple..

A distributor as disclosed herein may also be provided with apparatus within one or more chambers to direct or pump the water or to remove debris from the water.

Other apparatus may similarly be provided in one or more of the chambers, for example for monitoring purposes such as temperature, pH or the like.

For example, a circulation pump may be arranged such that the pump propeller is disposed within a chamber of the distributor so as to drive water from one chamber to another chamber and through part or all of the distributor. Similarly, a filter may be disposed within a chamber to remove particulates from the water flow.

Furthermore, a valve may be arranged to direct water from one or more chambers into another chamber thereby providing a selectable flow path though the distributor.

In the arrangements where a circulation pump and/or valve is used, the drive means for the valve or pump are preferably disposed outside of the outer wall with a drive member extending into the distributor outer wall (for example through an inlet or outlet port) so as to drive the pump propeller or valve closure means.

Debris may be removed from the water by the use of a filter such as a mesh filter or any suitable filter type. However, a build up of filtered material can block the filter and impair operation of the filter unless it is regularly cleaned. Consequently it is preferred to us a centrifugal or turbulence driven device to remove debris from the water. In a preferred embodiment this is a SpiroventR dirt collector of the type manufactured by Spirotech, which uses a cylindrical chamber having a mesh within it and being arranged to generate turbulence. This type of device does not use a filter element but instead the dirt or debris is separated from the water by turbulence and collects in an area of no flow, where it can then be easily removed through a suitable valve or outlet, if required. In this context dirt or debris is generally particulate matter in the water, which may arise from material deposited in the pipe work or fluid components during manufacture or construction, or from corrosion, in particular rusting of ferrous metals. By use of a SpiroventR type dirt collector the dirt or debris can comprise very small particles which may not be readily collected by even a fine filter. This type of collector can also collect air to avoid an undesirable build up of air in the system in which the distributor is installed.

Viewed from a second aspect the present invention provides a method of manufacturing a distributor for a central heating system, the distributor having one or more passageways between at least one inlet port and at least one outlet port, the method comprising: providing an outer casing in the form of an outer wall that encloses a series of chambers, the chambers forming the passageway(s), wherein the outer wall forms part of a wall of at least one of the chambers.

By arranging an outer wall in this way a distributor as discussed above can be easily produced. In preferred embodiments, the method includes providing the preferred features of the distributor described above.

The method may include defining an elongate shape with the outer wall, and providing a chamber wall extending along the length of the elongate shape to produce two elongate chambers. Additional chamber walls may divide the distributor into more elongate chambers.

One or more cross plates may be provided across the width of the elongate chambers to divide them into two shorter chambers, or to form an end plate of the distributor. The cross plates may be as described above. The method may include cutting slots into the distributor to fit the cross plates. The slots preferably comprise slots cut from two faces of the distributor, leaving tabs forming connecting portions between the two slots which join the two lengths of the distributor divided by the slots. The cross plates may be provided with recesses to accommodate the tabs.

Preferably the recesses are sized to closely fit around the tabs. The cross plate may have a hole at one end that opens onto the recess.

With this arrangement the method may include placing the cross plate partially in the slot with a tab in the hole, and rotating the cross plate about the tab into the slot.

Once the cross plate is rotated into the slot it may then be slid across to engage the tabs in the recesses. A plug may be fitted into the hole. Alternatively, the hole may form a flow path between two chambers either side of the cross plate.

This cross plate design and method of fitting allows the distributor to be produced in the form of a long outer wall, which may be extruded, and this can then be easily divided into sections along its length.

Holes may be provided between the various chambers to create the passageways. Valves may be provided to control the passageways and to control water flow along the passageways between inlets and outlets.

Preferably the method comprises assembling the distributor parts into place, and brazing the joints to form a sealed unit. Brazing is ajoining process whereby a non-ferrous filler metal or alloy is heated to melting temperature (generally above 450 C; 800 F) and distributed between two or more close-fitting parts by capillary action. At its liquid temperature, the molten filler metal and flux interacts with a thin layer of the base metal, cooling to form an exceptionally strong, sealed joint due to grain structure interaction. The brazed joint becomes a sandwich of different layers, each metallurgically linked to the adjacent layers. Brazing is particularly advantageous in applications using water, as it forms a corrosion resistant joint compared to other joining methods, such as welding.

In a preferred embodiment the brazing is carried out by depositing the brazing filler material, preferably nickel or a nickel based solder, onto the joints, and heating the entire distributor, for example in an oven. This allows all the joints to be secured and sealed at once, resulting in a better quality product and reduced manufacturing time and cost.

It is particularly advantageous to use this brazing method in conjunction with the cross plates described above, as then the fixing and sealing of the chamber walls as well as dividing plates and end plates can be all achieved in a single brazing step.

In addition, the use of slots between two sections of the distributor for inserting the cross plates means that expansion of the distributor under heating has a minimal effect on the clearance between the plate and the edges of the slots. This is important for brazing in particular, as brazing is sensitive to the size of the gap which is use to generate the required capillary action.

Viewed from another aspect, there is provided a distributor, preferably a central heating water distributor, comprising at least one inlet port and at least one outlet port and one or more passageways defined therebetween, wherein the passageway(s) is/are formed of a series ofchambers and wherein the walls of at least one of said chambers are arranged to surround the remaining chambers.

Viewed from a still further aspect, an invention disclosed herein provides a distributor comprising at least one inlet port and at least one outlet port and one or more fluid passageways defined therebetween, wherein the fluid passágeways is/are in the form of a series of substantially parallel elongate chambers and wherein the walls of at least one of said chambers are arranged to surround the remaining chambers, Preferably, as discussed above, the parallel elongate chambers are formed by U-shaped elongate members in a stacked arrangement with apertures suitably arranged in said members to define the required flow path. The U-shaped members are preferably substantially wide and shallow i.e. the vertical sections of the U' are substantially shorter than the horizontal section of the U' profile.

Viewed from a further aspect the invention provides a fluid distributor comprising two outer members on either side of an inner member, wherein the inner member is provided with channels forming passageways arranged to extend between various inlet and outlet ports provided in the outer members so as to define flow paths through the distributor.

Thus, fluid can be distributed between fluid components utilising internal passageways which are channels in a layer of a laminate' structure. The outer members are placed against the inner member over the channels in order to seal the channels. This distributor may be formed of two substantially flat outer members with a series of inlet and outlet ports arranged to communicate fluid into and out of the distributor. The passageways in the inner member may be formed by a milling or other similar suitable manufacturing process.

A distributor of this type is particularly suitable for use in applications where small flow capacities are required at low pressures. To provide a distributor of this type for use with higher flow rates at higher fluid pressures the distributor may include a substantial outer housing or casing to contain the pressure. The housing or casing resists separation forces that act to push apart the two outer members and that are generated as a result of the large surface areas of the channels and the pressure of the fluid within the channels.

Viewed from yet another aspect, there is provided a fluid circulation pump arranged for connection to a fluid distributor as described herein, the distributor comprising at least one internal chamber, wherein the fluid circulation pump comprises a drive means and a fluid propeller coupled thereto and wherein the fluid propeller is disposed in use within the at least one internal chamber of the distributor.

Viewed from a still further aspect, there is provided a valve arranged for connection to a fluid distributor as described herein, the distributor comprising at least one internal chamber, wherein the valve comprises a drive means and a valve closure member coupled thereto and wherein the valve closure member is disposed in use within the at least one internal chamber.

In such an arrangement the closure member may for example be arranged to close an aperture of a chamber or may alternatively be arranged to direct flow into or out of a chamber selectively to one or more other chambers.

A central heating system incorporating a distributor of a type described herein may be arranged to receive heat, in the form of hot fluid (for example water), via a heat exchanger. It may in this arrangement be preferable to connect a primary (hot) side of the heat exchanger to a first distributor of a type described herein and a second (cold) side of the heat exchanger to a second distributor of a type described herein.

Thus, in such as arrangement, a pair of distributors is provided, one connected to each side of a heat exchanger. The primary circuit may thereby be fluidly connected to a heat source via the primary circuit distributor and the secondary circuit to respective heat consumers such as a radiator, heat store and the like.

It will be recognised that aspects of inventions disclosed herein may conveniently and advantageously be used in any suitable combination.

Whilst the description herein generally refers to distributors of the type used in central heating arrangements it will be appreciated that such a distributor can be used in other applications where interconnections are required, and with fluids other than water.

Preferred embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which: Figure IA shows a convention arrangement of pipes for connecting various fluid components, Figure lB shows a laminate distributor structure, Figure 2A shows an exploded view of a modified distributor according to an embodiment of the present invention, Figure 2B shows a cross-section through section A-A' in Figure 2A of an assembled distributor, Figure 3 shows a cross-section through section B-B' in Figure 2A of an assembled distributor, Figure 4A shows a front view of a distributor showing two adjacent distributors, Figure 4B shows a cross-section, corresponding to section B-B' in Figure 2A, for the adjacent distributor shown in Figure 4A, Figure 4C shows a plan view in cross-section of the first and adjacent distributors shown in Figure 4A, Figure 5 shows an alternative extruded construction of a distributor in accordance with an invention, Figure 6 shows a cross-section of an embodiment of a distributor incorporating a circulation pump and fluid control valve, Figure 7 is a cross-section through the width of an alternative distributor arrangement, Figure 8 is a cross-section through the width of another alternative distributor arrangement, Figure 9A is a cross-section along the length of an embodiment of a distributor having four inlet/outlet ports and various other components attached, Figure 9B shows a cross-section through the width of the distributor of Figure 9A, Figure IOA is an exploded view of a distributor similar to that shown in Figures 9A and 9B, Figure lOB is a cross-section of the distributor of Figure 1OA when assembled, Figure II is a view showing detail of the connection of the valve shown in circle X in Figure 9B and Figure lOB, Figure 12 is a view showing detail of the connection of the dirt and air collector shown in circle Y in Figure 9B, Figure 13A is a side view of a section of a distributor with a pump and a dirt collector fitted, Figure 1 3B is a cross-section of Figure 13A Figure 13C shows the distributor section of Figure 13A viewed from the right as seen in Figure 13A.

Figure 1 3D shows a cross-section along line C-C' of Figure 1 3A, Figure 13E shows a cross-section along line D-D' of Figure 13A, Figure 14 shows a twin distributor arrangement, Figures ISA to I 5D show various stages in the fitting of cross plates in a section of a distributor, Figures 1 6A to 1 6D are cross-sections showing a view along the distributor corresponding to the various stages shown in Figures 1 5A to I 5D, and Figure 1 7A and Figure 1 7B show a perspective view and a plan view respectively of a distributor being fitted with cross plates.

Figure lB shows a laminate distributor arrangement 1 providing one means to interconnect fluid components in a small space. The distributor comprises two substantially flat outer members 2, 3 having a series of inlet and outlet ports 6, 7 arranged to communicate fluid into and out of the distributor. The flat outer members comprise a front member 2, a rear member 3 and in between them is an inner member 4. The inner member 4 is provided with passageways 5 connecting inlet and outlet ports 6, 7 provided in the inner member 4, which are arranged to align with corresponding ports 8, 9 in the front member 2. In use the port 8, 9 would be connected to components of the heating system so as to provide a flow path therebetween. The passageways 5 are generally formed by a milling or other similar suitable manufacturing process. Such an arrangement, as shown in Figure 1 B, provides a generally thin arrangement which can distribute fluid between a number of components.

Figure 2A shows an exploded view of one half of a preferred embodiment of a distributor 10. The complete distributor is formed of two elongate members of the type shown in figure 2A arranged side by side. This is described in detail below.

Referring again to Figure 2A, the distributor 10 comprises a front elongate member 11 and a rear elongate member 12, formed of steel or, in an alternative embodiment, of aluminium. The rear member 12 has a semi-circular cross-section and is formed of a steel section folded into a generally U shaped profile. The front member 11 is formed of steel sheet and is provided at either end with perpendicular portions extending from the front member Ii. The perpendicular portions are provided with profiles (as shown) arranged to match the rear portion curvature such that the front and rear members cooperate and can be joined together to form a sealed outer distributor body or outer wall.

The front member 11 has a 5 mm wall thickness when steel is used and a 10 mm wall thickness where aluminium is used. The rear member 12 has a 1 mm thickness when steel is used and a 2 mm wall thickness when aluminium is used.

The front member 11 is provided with a number of apertures 1 3a -I 3g extending through the member and providing inlet and outlet ports to the distributor.

Each aperture is provided with a corresponding collars 14 extending from the outer surface of the front member 11 to which the necessary heating installation components or conduits can be connected.

The channels or passageways within the distributor are provided by a series of members positioned within the distributor outer wall. In the embodiment shown in Figure 2A, two internal members 15, 16 are provided, which form the internal chamber walls. The internal members 15, 16 are pressed steel parts and are provided with partition sections 17, 18 in the form of cross plates, and apertures 19-24.

The inner members 15, 16 have a wall thickness of 2 mm when steel is used and a 3 mm wall thickness when aluminium is used.

The distributor is constructed as follows. The inner member 15 is first coupled to the inside surface of the front member 11 against which the edges of the inner member are sealed, for example by welding. This thereby creates a first, second, and third chamber (25a, 25b and 25c respectively). Similarly, the inner member 16 is coupled to the rear surface of the inner member 15 (as indicated by the arrow 26 shown in figure 2). The edges of the inner member 16 are sealed, for example by welding, to the rear surface of the inner member 15 thereby creating a fourth and fifth chamber 27a, 27b.

In the particular embodiment a conduit 28 which, once the distributor has been constructed, is provided which extends from the front member 11 through the inner members 15, 16 to the chamber defined between the inner surface of the rear member 12 and the inner member 16.

A cross sectional view A-A (reference Figure 2A) of the distributor can be seen in figure 2B. Figure 2B illustrates the front member 11, rear member 12 and the inner members 15, 16. At the particular cross-section A-A', the internal distributor chambers 25b, 27b and the chamber 29, located between the rear member 12 and inner member 16, can be seen. It will be appreciated from Figure 2A that the inner member 15 extends over a number of apertures provided in the front member 11 and that the inner member 16 extends over a number of apertures provided in the inner member 15. This is shown in more detail in Figure 3.

Figure 3 shows a cross-section through section B-B' shown in Figure 2A.

Figure 3 also shows some of the components which are coupled to the distributor.

These are described below.

In Figure 3 the front and rear members ii, 12 are shown together with the inner members 15, 16. The chambers 25a, 25b and 25c in respect of the inner member and chambers 27a and 27b in respect of the inner member 16 are visible. The rear chamber 29 is also shown. The chambers (defined by the positioning of the inner members 15, 16 and the partitions 17, 18) are arranged to extend over respective apertures I 3a-1 3g so as to define flow paths in and out of the respective chambers.

As can be see in the cross-section in Figure 3, each of the apertures 13a to 13g is fluidly connected to a chamber. For example, aperture I 3b is coupled to chamber 25c and is thereby fluidly connected to aperture 13c. Similarly aperture 13a is coupled via chamber 29 to the aperture 30 located at the upper end of the distributor. The various fluid connections to the respective chambers will be apparent from the cross-section shown in Figure 3.

Figure 3 also illustrates some of the components used in one application of the distributor. In the arrangement shown there is provided a heat exchanger 31 which is fluidly connected to the chambers 29 and 25a, a pump 32a arranged to pump fluid within chamber 25a and a valve 33 arranged to direct fluid flow between chambers.

The operation of commercially available heat exchangers, pumps and valves (which may be used in conjunction with a distributor described herein) is not described in detail in the present application.

As shown in Figure 3, an arrangement of a distributor according to the present invention provides a substantially thin arrangement i.e. the depth of the distributor from the front to the rear members is small.

The curvature of the rear member 12 advantageously minimises the thickness of material needed to accommodate higher pressures in the same way that a cylindrical vessel provides an optimal shape as a pressure vessel. In this way the wall thickness of the member 12 can be minimised.

As shown in Figure 2B, the inner members 15, 16 are contained entirely within chamber 29 which is defined by the rear curved member 12 and front member Ii. Thus, the front and rear members 11,12 define a wall having atmospheric pressure acting against the exterior and the pressure of the fluid acting against the interior.

As a result of the flow path through the distributor chambers each of the chambers is at substantially the same pressure i.e. the pressure in chambers 25b, 27b and 29 are substantially the same. It will be appreciated that this is also the case in respect of the other chambers. There is therefore no or substantially little pressure differential across the inner member 15, 16 walls and the wall thickness of each member can therefore be minimised. This minimises the size, weight and complexity of the distributor components.

Figure 4A shows a front view of an embodiment of the present invention in which two substantially similar distributors 10 (as shown in Figure 2A) are positioned adjacent one another. In this arrangement the second member lOb is provided with two apertures 34, 35 for connection to for example a heat source. Figure 4B shows the second distributor I Ob in cross-section and the apertures 34, 35 communicating with chambers within the distributor in the same way as described with reference to Figures 2A and 3.

Figure 4C shows a plan view in cross-section of the distributor 10, lOb and the respective chambers.

A distributor arrangement according to a preferred embodiment of the present invention operates as follows. Aperture 35 is arranged to receive hot water from a heat source (not shown). The hot water passes through the chambers, by means of pump 32b, within distributor lOb and through the primary circuit of heat exchanger 31. The return water from the primary circuit then flows through the chamber 36 to the aperture 34 where the water is returned to the heat source for reheating.

The secondary side of the heat exchanger, as shown in Figure 4A, is fluidly connected to the first distributor 10 as shown in Figures 2A and 3 A. Fluid in the secondary circuit is distributed from the heat exchanger, by means of pump 32a, through the chambers in the distributor 10 to and from the apertures I 3a to 1 3g which are connected to components of the heating installation. For example, the apertures may be connected to a heat store, radiators, filters, pumps, supplementary heating means and so forth. The secondary circuit water is then returned to the heat exchanger 31 for reheating.

The arrangement of the distributor minimises the complexity of construction and the material required. The front member 11 and inner members 15,16 are formed of pressed steel and are welded to one another to provide the chambers described above. The rear member 12 is simple folded steel member.

In an alternative embodiment, the front member and inner members may also be formed of an extrusion (such as aluminium or a suitable plastic material) as shown in Figure 5.

Figure 5 shows a cross-section through the distributor 10, 1 Oa and the respective chambers corresponding to cross-section A-A' in Figure 2A. Partitions corresponding to reference numerals 17 and 18 in Figure 2A can be connected to the extrusions as required to define the required chambers.

Figure 5 also illustrates the complex internal profile which can be achieved by means of an extrusion. An extrusion can be used to form both the inner and outer members of the distributor which can also be formed as a single elongate extrusion.

In the embodiment shown in Figure 5 the distributor are further provided with a wall 37 and supports 38 to provide a cavity 39 around the distributor. The cavity is filled with an insulating material to insulate the distributor from the surrounding conditions.

It will be appreciated that all of the flow paths between the chambers for the embodiments described herein cannot be seen in each cross-section because of the positioning of the respective apertures and the cross-section itself. It will nevertheless be appreciated that the chambers are each interconnected so as to provide flow paths between components/inlet and outlets in accordance with the intended use of the distributor.

It will also be appreciated that any arrangement of internal members, apertures and partitions may be used to achieve the desired flow path within the distributor and S that features of each and any embodiment described herein may be used in isolation or in combination.

Figure 6 shows a cross-section of a distributor according to an invention disclosed herein incorporating a circulation pump and fluid control valve. Figure 6 shows a close up view of a circulation pump 32a and valve 33 of the type shown in Figure 3.

The circulation pump 32a comprises a main body 40 containing an electric motor (electrical connections not shown). The electric motor is mechanically coupled to a drive shaft 41 which is in turn coupled to a propeller 42. The propeller is provided with a plurality of vanes which, on rotation, act to propel the fluid.

As shown, the main body is connected to the front member 11. The propeller extends into the first chamber 43 which is provided with an aperture 44 opening into a second chamber 45.

Figure 6 also shows valve 33 having a housing 46 and a drive shaft 47 coupled to a closure member 48. The housing 46 contains an electric motor (or actuator) arranged to operate the closure member on receipt of control signals from a control system (not shown).

The closure member 48 is disposed within chamber 43 and is arranged to allow fluid to flow from the first chamber 43 to the third chamber 49.

Thus, it can be seen that by incorporating appropriate closure members a valve of the type shown in Figure 6 can be used to selectively permit or prevent flow through different paths within the distributor in response to appropriate control signals.

The arrows 50 illustrate the flow of fluid from chamber 45, through the propeller 43 to the vale closure member 47.

The arrangement shown in Figure 6 may be duplicated in the second parallel distributor shown in Figure 4B.

En an alternative arrangement where a pump is not provided in chamber 43 and there is no aperture 44 connecting chambers 43 and 45, the closure member 48 may extend into chamber 45 by means of a suitable aperture between chambers 45 and 49 and may be arranged to selectively direct flow from chambers 42 and 45 to chamber 49 (or other combination thereof). In such an arrangement the valve may operate in effect as a mixing valve.

Figures 7 and 8 show alternative configurations which can achieve an elongate distributor that is split into elongate chambers. In Figure 7 an outer wall of the distributor is formed from two shallow U-shaped sections II, 12 placed face to face with a partition 15 between them. Thus, two chambers are formed. In Figure 8, U-shaped sections similar to those in Figure 7 are stacked facing the same way, with a further U-shaped section placed to face the bottom section on the stack. Thus with this arrangement three chambers are formed, each separated by internal chamber walls 15, and enclosed by the outer wall, which comprises the two end sections and parts of the middle sections.

Figure 9A is a cross-section along the length of a distributor which has three elongate chambers, a top chamber 43, a middle chamber 45, and a bottom chamber 49. The three elongate chambers (or layers) are further provided with partition sections (similar to 17 and 18 in Figure 2A) in the form of cross plates, and apertures.

There are three such cross plates in 43 and there are five such cross plates in 45.

These can be seen in more detail in the embodiment shown in Figures 1 OA and 1 OB, which is similar to the embodiment of Figures 9A and 9B. Four inletioutlet ports pass through the chambers, comprising a flow port 60, return port 61, bottom heat storage port 62 and top heat storage port 63. By having the inlet/outlet ports pass through the chambers, it is possible to connect to both sides of the distributor. It also makes it possible to use several distributors in parallel as discussed below in relation to Figure 14, which makes installation of more than one distributor much more convenient.

When the distributors are mounted in parallel, the ports 60 to 63 not only acts as ports for the specific unit, but also acts as mere pipes viewed from the other manifolds.

Two circulation pumps 32 are connected to either end of the top chamber. The pumps 32 have an inlet 64 and outlet 65, and pumping vanes 66.

The flow port 60 connects a section of the middle chamber 45, with a section of the top chamber 43. The return port 61 and bottom heat storage port 62 connect a different section of the middle chamber 45, with a different section of the top chamber 43. The top heat storage port 63 communicates with the bottom chamber 49.

As can be seen in Figure 9B, which is a side view of Figure 9A from between the return port 61 and bottom heat storage port 62, the chambers 43,. 45, 49 are formed by two chamber walls 15, 16. The first chamber wall 1 5 is a shallow U-shaped section which faces onto the outer wall, thus enclosing the top chamber 43.

The second chamber wall 16 is a smaller U-shaped section which faces onto the first chamber wall, thus enclosing the middle chamber 45. The bottom chamber 49 is the remainder of the space enclosed by the outer wall.

Two valves 33a, 33b are placed to control flow of fluid. The left hand valve 33a is a two way valve which controls flow of fluid between the top and middle chambers. The right hand valve 33b is a three way valve, which controls fluid flow between all three chambers 43, 45, 49. A dirt arid air collector 67 is installed to remove air and dirt from the fluid.

The distributor shown in exploded view Figure 1 OA is similar to that shown in Figures 9A and 9B, but the positions of the top and bottom heat storage ports 62, 63 are reversed, and a different arrangement is used to connect the dirt/air collector 67.

Figure I OA shows more clearly the apertures and cross plates or partitions 17, 18 that together with the main chamber walls define the various passageways in the distributor. Figure lOB is a cross-section of the distributor of Figure 1OA when assembled.

The various parts and fluid connections in the embodiment of Figures 1 OA and lOB are as follows. The top, middle and bottom chambers 43, 45, 49 are enclosed by a first chamber wall 15, a second chamber wall 16 and the outer wall 102. When assembled, the first chamber wall 15 faces onto the outer wall 102 and the second chamber wall 16 faces onto the first chamber wall 15 in the same manner as the arrangement shown in Figure 9B.

The bottom chamber 49 is connected to a source of hot water via an inlet port (not shown) which is on the side of the outer wall 102, and an aperture 103 connects the bottom chamber 49 to a section 45a of the middle chamber 45 at the left hand end of the Figures. The top heat storage port 63 also opens into the bottom chamber 49.

Finally, the bottom chamber 49 can be connected to a section 45b of the middle chamber at the right hand end using the three way valve 33b, which also connects to a section 43b of the top chamber. The right hand section 45b of the bottom chamber communicates with the right hand circulation pump via pump inlet 64.

From the left hand section 45a the pump inlet 64 communicates with the left hand circulation pump, and the outlet 65 of this pump passes fluid into a left hand section 43a of the top chamber 43. Communication between this section 43a and a first central section 45c of the middle chamber is controlled by a two way valve 33a.

The central middle section 45c is connected by a large aperture 104 to a central section 43c of the top chamber, and this combined chamber 43c, 45c communicates with the flow port 60.

The return port 61 and the bottom storage port 62 both connected into a second central section formed by a the right hand top section 43b, which extends across the central area of the top chamber 43, and a second central middle section 45d, which are connected by a large aperture 105. As discussed above, the second central top section 43b can connect onward to the right hand middle section 45b and thence to the pump inlet 64 and bottom chamber 49 via the three way valve 33b.

At the far right of the top chamber 43 a final section 43d communicates with pump outlet 65 and via an aperture 108 opens into a filter or dirt collector chamber 109 formed across the far right hand ends of the middle and bottom chambers 45, 49.

As can be seen in Figure lOB, the filter chamber 109 connects with a filter outlet chamber 110, and then to an outlet port 107, which provides a connection back to the heat source.

Thus, in one mode of operation hot water enters the bottom chamber 49 via the inlet port, and is pumped by the left hand pump through the two way valve 33a to the flow port 60. This port 60 can then provide a supply of hot water to fluid components connected to the distributor. Water returns from the fluid components via return port 61, and can pass via the three way valve 33b and the right hand pump to the filter chamber and is then returned to the heat source via outlet port 107.

The top and bottom heat storage ports 62, 63 allow hot water to be supplied to storage via the top heat storage port 62 from the bottom chamber 49, and cool water can be returned to the heat source from the bottom heat storage port 63 through the three way valve 33b and the right hand pump to the filter chamber and finally exiting the distributor via outlet port 107. Alternatively, the top heat storage port 63 can be usedto supply hot water to the bottom chamber 49 in order to allow stored heat to be used instead of using hot water entering from the inlet port.

Figure II is a view showing detail of the connection of the three way valve 33b shown in circle X in Figure 9B or JOB. This valve 33b connects between the top chamber 43, the middle chamber 45, and the bottom chamber 49. The valve 33b has a housing 46, a drive shaft 47 and a closure member 48. In the shown configuration there is relatively hot water in the bottom chamber 49 and relatively cold water in the top chamber 43. The pumps 32 at either end of the distributor draw water through the 3-way valve where the water is mixed. Thus the valve acts as a mixing valve between the cold water in the top chamber 43 and the hot water in the bottom chamber 49. The piston 48 in the middle of the valve is moveable, and when in top position it prevents flow from the top chamber 43 and when in bottom position it prevents flow from the bottom chamber 49. The piston 48 may be moved by a spindle 47 or any other convenient measure. Also the 3-way valve may be of any convenient design, for instance a rotating valve as shown in Figure 6 is another possibility.

Figure 12 is a view showing detail of the connection of the dirt and air collector 67 shown in circle Y in Figure 913. This collector 67 is known as a micro bubble deaerator and has the advantage that even vary small air bubbles (micro bubbles) is separated from the water. Also similar or equal technologies is used to collect dirt from large particles down to very small particles. One known type as supplied for example by Spirotech Ltd under the name SpiroventR. As can be seen in Figure 12, the collector 67 has its inlet/outlet in the middle chamber 45 and there is a similar inlet/outlet to chamber 43 such that water will pass through the filter/collector.

The inlet/outlet to chamber 43 is provided with a number of relatively small holes surrounding the collector 67.

Figures 1 3A to 13E show an alternative arrangement of a dirt collector 67 and also a pump 32 fitted to a section of a distributor similar to that shown in Figures 1OA and lOB. The pump 32 is as previously discussed, and has its inlet 64 taking fluid from the middle chamber 45, and its outlet 65 pumping fluid into the top chamber 43.

The dirt collector 67 has an inlet 69 in the top chamber 43 and is fitted within the distributor extending through a section of the middle and lower chambers. The outlet 71 of the dirt collector 67 passes fluid out of the distributor and thus on to other components. As discussed above similar arrangements may be used for collecting air and micro bubbles. To release the collected air in an air collection arrangement, it is preferred to use an automatic air release valve. Similarly, means must also be in place to get rid of collected dirt, for example one commonly used way is simply to add a valve in the bottom of the dirt collector 67.

As shown in Figure 14, the distributor of Figures 9 to 13E can be used in a twin distributor arrangement, in which each distributor box 68 contains two parallel S distributors and a heat exchanger between them as in Figure 4A. The various ports 60, 61, 62, 63 pass through both of the distributors 10, and each distributor has its own connections 73 to the heat source. This setup is highly advantageous when more than one heat source is provided, especially when the heat sources are CHP units that requires separate and accurate heat control and thus separate heating circuits. The installation of this setup becomes both easy and need since only straight piping is needed.

Figures 15A to 15D and corresponding Figures 16A to 16D show various stages in the fitting of cross plates 74 in a section of a distributor. The cross plates divide the distributor across the width of the elongate chambers form shorter chambers, or to form an end plate of the distributor. The distributor has slots 77 for fitting the cross plates 74. For clarity, the end of the distributor is not show in Figures 1 5A to 1 5C nor in Figures 1 6A to I 6C. The end of the distributor is shown in Figure 1 5D, in which a short overhand 78 is provided to allow the slot 77 to be formed. The slots cut across the distributor from either side and leave tabs 79 holding the two parts of the distributor together. The cross plates 74 have recesses 75 to accommodate the tabs 79, and a hole 80 at one end.

To assemble the cross plate 74 into the distributor the cross plate 74 is placed partially in the slot 77 with a tab 79 in the hole 80 as shown in Figures 1SA/16A.

Then the cross plate is rotated about the tab into the slot 77, to take up the position shown in Figures 15B/16B. Once the cross plate 74 is rotated into the slot 77 it is then slid across to engage the tabs 79 in the recesses 75, in the position shown in Figures 1 5C/1 6C. A plug 81 may be fitted into the hole 80. This plug 81 can be fitted either from the end of the distributor, or if the cross plate 74 is a dividing plate in the centre of the distributor then the plug 81 can be fitted using the port 82 to access the inside of the distributor.

The cross plate can include a hole for passage of fluid between one or more chambers, thus forming a partition for only one of the chambers. A cross plate 74 t having a hole is shown in Figure 1 5A. Lugs 83 can be used to fit the cross plate 74 into place if required.

Figure 17A and Figure 178 show a perspective view and a plan view respectively of a distributor similar to that of Figures 1 5A to I 5D and Figures 16A to 16D being fitted with cross plates 74. In this case a partitioning cross plate is being fitted at a centre of the distributor.

In the Figures just described, the cross plate 74 is a flat generally rectangular plate. However, it can also be a plate with a protruding boss and connecting brackets for connection to other components as in the case of the cross plate fitted as an end plate in the embodiment of Figures 1OA and lOB.

The distributor described above is manufactured by assembling the distributor parts into place, and brazing the joints to form a sealed unit. The brazing filler material, which is nickel or a nickel based solder, is placed onto the joints, and the entire distributor is heated in an oven. The brazing material is melted and drawn by capillary action into the joints, which are then secured and sealed.

Claims

Claims: I. A distributor for distributing water in a central heating

system, comprising at least one inlet port and at least one outlet port and one or more passageways defined therebetween, wherein the passageway(s) is/are formed of a series of chambers enclosed by an outer casing formed by an outer wall, wherein the outer wall forms part of a wall of at least one of the chambers.

2. A distributor as claimed in claim I, wherein the outer wall forms a pressure chamber that contains the pressure within the distributor.

3. A distributor as claimed in claim I or 2, comprising a chamber wall within the outer wall, wherein chambers are formed by the spaces enclosed between the outer wall and the chamber wall.

4. A distributor as claimed in claim 3, wherein the outer wall is thicker than the chamber wall.

5. A distributor as claimed in claim 3 or 4, wherein the outer wall is formed of a stronger material than the chamber wall.

6. A distributor as claimed in claim 3, 4 or 5, wherein the chamber wall is a substantially U-shaped section enclosing an inner chamber by facing onto a part of the outer wall, and the remainder of the space enclosed by the outer wall forms an outer chamber.

7. A distributor as claimed in claim 6, comprising a second chamber wall, wherein the second chamber wall is a substantially U-shaped section enclosing a second inner chamber by facing onto a part of the first chamber wall.

8. A distributor as claimed in any preceding claim, wherein the distributor is an elongate shape comprising elongate chambers.

9. A distributor as claimed in claim 8, wherein the elongate chambers are divided into shorter chambers or sealed at their ends by cross plates.

10. A distributor as claimed in claim 9, wherein at least one of the cross plates is secured in slots cut into the outer wall.

II. A distributor as claimed in any preceding claim, comprising a plurality of inlet ports and outlet ports arranged to allow water flow into and out of the distributor.

12. A distributor as claimed in claim 11, wherein water can flow between the inlet ports and outlet ports along a plurality passageways in the distributor, to thereby distribute the water.

13. A distributor as claimed in any preceding claim, comprising a dirt collector for the collection and removal of dirt or debris in the water.

14. A distributor as claimed in any preceding claim, wherein the outer wall is formed of a generally square or rectangular cross-section.

15. A distributor as claimed in any preceding claim, comprising brazed joints sealing the chambers.

16. A distributor as claimed in any preceding claim, comprising a hole between adjacent chambers to form a passageway including the adjacent chambers.

17. A distributor as claimed in any preceding claim, comprising a valve, the valve arranged to control flow of fluid between two or more chambers, or between a chamber and an inlet/outlet port.

18. A distributor as claimed in any preceding claim, wherein the distributor is a central heating distributor. 4 4

19. A method of manufacturing a distributor for a central heating system, the distributor having one or more passageways between at least one inlet port and at least one outlet port, the method comprising: providing an outer casing in the form of an outer wall that encloses a series of chambers, the chambers forming the passageway(s), wherein the outer wall forms part of a wall of at least one of the chambers.

A method as claimed in claim 19, comprising providing a chamber wall within the outer wall to thereby form the chambers.

21. A method as claimed in claim 19 or 20, comprising forming the outer wall into a pressure chamber enclosing the other chambers.

22. A method as claimed in claim 19, 20 or 21, comprising defining an elongate shape with the outer wall, and dividing the space enclosed by the outer wall along the length of the distributor to produce elongate chambers.

23. A method as claimed in claim 22 comprising fitting a cross plate across the width of the elongate chambers to divide them into two shorter chambers, or to form an end plate of the distributor.

24. A method as claimed in claim 23, comprising cutting slots into the distributor to fit the cross plates.

25. A method as claimed in claim 24, wherein the slots comprise slots cut from two faces of the distributor to leave tabs on either side of the distributor between the two slots, the tabs forming connecting portions which join together the two lengths of the distributor divided by the slots.

26. A method as claimed in claim 25, comprising placing the cross plate partially in the slot with a tab in a hole in the cross plate, rotating the cross plate about the tab into the slot and sliding the cross plate along in the slot to engage the tabs in recesses in the cross plate.

27. A method as claimed in claim 26, comprising fitting a plug into the hole in the cross plate.

28. A method as claimed in any of claims 19 to 27 comprising assembling the distributor parts into place, and brazing the joints to form a sealed unit.

29. A method as claimed in claim 28, wherein the brazing is carried out by depositing a brazing filler material onto the joints, and heating the entire distributor.

30. A method as claimed in any of claims 19 to 29, wherein the method is a method of manufacturing a distributor as claimed in any of claims I to 18.

31. A fluid distributor comprising two outer members on either side of an inner member, wherein the inner member is provided with channels forming passageways arranged to extend between various inlet and outlet ports provided in the outer members so as to define flow paths through the distributor.

32. A distributor comprising at least one inlet port and at least one outlet port and one or more fluid passageways defined therebetween, wherein the fluid passageways is/are in the form of a series of chambers and wherein the walls of at least one of said chambers are arranged to surround the remaining chambers.

33. A fluid circulation pump arranged for connection to a fluid distributor as described herein, the distributor comprising at least one internal chamber, wherein the fluid circulation pump comprises a drive means and a fluid propeller coupled thereto and wherein the fluid propeller is disposed in use within the at least one internal chamber of the distributor.

34. A valve arranged for connection to a fluid distributor as claimed herein, the distributor comprising at least one internal chamber, wherein the valve comprises a drive means and a valve closure means member coupled thereto and wherein the valve closure member is disposed in use within the at least one internal chamber.

35. A distributor substantially as hereinbefore described with reference to figureslB,2Ato4C,5,6,7,8,9Atol4orl5tol8D.

36. A method of manufacturing a distributor substantially as hereinbefore described.