GB2359873A

GB2359873A - Twin boiler module

Info

Publication number: GB2359873A
Application number: GB0004726A
Authority: GB
Inventors: Martin John Duckett; Nigel Stokes
Original assignee: POTTERTON MYSON Ltd
Current assignee: POTTERTON MYSON Ltd
Priority date: 2000-02-29
Filing date: 2000-02-29
Publication date: 2001-09-05
Also published as: GB0004726D0

Description

2359873 TWIN BOILER MODULE

Field of the Invention

The present invention relates to boilers and apparatus for heating, and s particularly, although not exclusively, to a boiler unit having a plurality of heat engines, wherein said boiler units are modular and may be connected to other boiler units to provide a required thermal output.

Background to the Invention

It is known in the prior art to have wall-mounted or freestanding individual boiler units comprising a single heat engine. Individual boilers may be interconnected to increase a thermal output. It is further known in the prior art to combine a plurality of heat engines using copper fin heat exchange elements within a single apparatus to increase the thermal output from a single apparatus.

is It is not known to have boiler apparatus units having a plurality of heat engines specifically designed for ease of interconnection between header units enabling additional boiler apparatus units to be incorporated into a multi-unit system.

Although it is known in the prior art to combine a plurality of heat engines using fabricated heat exchange elements, such as copper fin heat exchange elements, within a single apparatus. It is not known in the prior art to combine a plurality of heat engines, one or more of which comprises a cast heat exchange element. Cast heat exchange elements include cast metal heat exchange elements. Said metal may include iron, aluminum, any other metallic element or 2s an alloy of metallic elements or an alloy of metallic and non-metallic elements. Cast heat exchange elements further comprise those heat exchange elements manufactured by casting, powder forming wherein a pellet of said cast metal is subject to pressure and thus takes the shape of a surrounding mould or cast and may include other methods of manufacture for producing heat exchange elements which do not comprise the fabrication of such elements by simple fixation of components by soldering or welding.

P547-spec It is also known in the prior art to have boiler apparatus units using single heat engines taking advantage of a room sealed or room opened system wherein a room sealed system may incorporate a balanced flue arrangement. A room open system thus intakes gas for combustion from the surrounding room wherein a room sealed system intakes air through a duct wherein outlet gases pass through a central pathway in the flue duct, and inlet gases pass around said central pathway.

It is not known in the prior art to include a plurality of cast metal heat exchange units in a single boiler apparatus unit. This is due to the heavy weight of cast metal heat exchange units. Cast metal heat exchangers carry with them the disadvantage of large size and weight required to produce a particular thermal output. Thus there is a technical problem in combining more than one heat engine having a cast metal heat exchanger within a single boiler apparatus unit. This problem includes the disadvantages of using cast metal heat exchange elements as they are normally large and heavy. Thus, in trying to produce a modular boiler apparatus unit which may be combined with other identical units to produce a bank of units acting in concert, there is an increasing problem of the amount of space taken up by such units and therefore their practicality in installation and use. Thus the prior art leads away from the use of a plurality of heat engines having cast metal heat exchange elements wherein the encompassing boiler apparatus unit has a small floor surface footprint.

is There is also a technical problem to overcome when manufacturing boiler apparatus units which may be required for use in a number of circumstances. In particular, there is the technical problem associated with the different arrangements of flue outlets possible and their necessary applications and different circumstances. That is, a single boiler apparatus unit known in the prior art is usually configured for only one flue arrangement.

Summajy of the Invention

The inventors have realized that existing lightweight cast metal heat exchange elements may be included in heat engines to produce a large thermal output by using small heat engines, and thus decreasing weight, and arranging those heat engines in vertical alignment to decrease the floor space footprints of each boiler unit. By decreasing the floor space footprint of each boiler unit a plurality of boiler apparatus units may be aligned and connected together via integral headers within each unit to provide a required thermal output which may be tailored to meet a demand by using a specific number of boiler apparatus units lo together.

The inventors have further realized that by using prior art heating engines having prior art flue ducting, a boiler apparatus unit may be provided wherein a kit may be provided to the installer comprising flue ducting and joints such that a particular flue ducting requirement may be accommodated by simple adjustment of a boiler apparatus unit to take advantage of either a room open or room sealed system which may incorporate a common flue system or independent flue ducting from each heat engine which may further incorporate a balanced flue system if required. Thus, the inventors have provided a multi-functional integral boiler apparatus unit having more than one heat engine to provide increased thermal output whilst keeping a small floor space footprint whilst the unit is compatible with a number of flue arrangements and is easily connected to adjacent units via internal headers for feed and return of water.

According to a first aspect of the present invention there is provided a boiler apparatus unit comprising:

a chassis; having a first end and second end and supporting supporting two or more heat engines; wherein said heat engines comprise cast metal heat exchange elements.

Preferably said cast metal is cast iron and said boiler apparatus is a noncondensing boiler apparatus.

Preferably said cast metal is cast aluminum and said boiler apparatus is a condensing boiler apparatus.

Preferably said boiler apparatus is configured for use as a freestanding or lo wall-mounted unit.

Preferably said boiler apparatus has a unit footprint of, or smaller than, 0.4 2 m.

Preferably said heat engines are vertically aligned.

Preferably said boiler apparatus has a plurality of heat engines wherein each heat engine has an integral header supply taken from a header feed wherein said header feed is connected to an adjacent boiler apparatus by connecting means thus forming a continuous header feed between adjacent boiler apparatus.

Preferably there is more than one boiler apparatus placed adjacent to each other and having a header feed interconnected by connecting means between 2s each of said boiler apparatus.

Preferably there are a plurality of boiler apparatus connected together by interconnecting headers wherein said boiler apparatus operate in concert to produce a required thermal output.

Preferably said heat engines are configurable for use with either a room sealed flue system or a room open flue system.

Preferably said heat engines share a common flue.

Preferably said flue system is a balanced flue system.

Preferably said boiler apparatus has heat engines configured for use with a room sealed flue system comprising separate flue ducts extending from each of lo said heat engines, each to a separate terminal portion.

Preferably said boiler apparatus has flue ducts comprising an inner and outer pathway for transmission of inlet and outlet gases to and from heat engines by means of a balanced flue system.

Preferably said boiler apparatus for a room open flue system comprises a first flue duct extending from each of said heat engines, said first flue ducts joining a second flue duct, said second flue duct providing a pathway for transmission of outlet gases to a terminal portion.

Preferably said boiler apparatus comprises a room open flue system further comprising a flue duct extending from each of said heat engines, each of said flue ducts providing a pathway for transmission of outlet gases to an independent terminal portion.

Preferably said boiler apparatus includes flue ducts comprising a pressure sensor arrangement operable to de-activate one or more of said heat engines in response to a change in pressure of said flue ducts.

According to a first specific method of the present invention there is provided a method of installation of a boiler apparatus unit comprising the steps of:

connecting said boiler apparatus to a gas supply; connecting said boiler apparatus to a water supply by header feed flanges; connecting flue ducts to further flue ducting to transfer outlet gases.

Preferably said method further comprises:

placing more than one boiler apparatus adjacent each other; interconnecting adjacent boiler apparatus water supplies via interconnecting header feeds.

Preferably said method further comprises the step of connecting flue ducts to a central flue duct system.

Brief Description of the Drawings

For a better understanding of the invention and to show how the same may be carded into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which:

Fig. 1 illustrates an external perspective view of a single boiler apparatus unit comprising two heat engines.

Fig. 2 illustrates an external view of a bank of boiler apparatus units linked together by interconnecting header supplies such that the boiler apparatus units can operate in concert to produce a required thermal output.

Fig. 3 illustrates a perspective view of an alternative arrangement of a plurality of boiler apparatus units. Four boiler apparatus units are arranged in a cuboid shape and represent a freestanding embodiment of a multi-unit modular 5 arrangement.

Fig. 4 illustrates in perspective view the boiler apparatus module shown in Fig. 1 with the external cover removed, thus revealing the two heat engines, header supply tubes and valves, flue ducting and supporting chassis.

is Fig. 5 illustrates the boiler apparatus module shown in Fig. 4 in side view.

Fig. 6 illustrates the boiler apparatus module illustrated in Figs. 4 and 5 in plan view.

Fig. 7 illustrates the boiler apparatus module shown in Figs. 4, 5 and 6 in endon view.

Fig. 8 illustrates three alternative embodiments which may be used to outlet gases through appropriate flue ducts. Fig. 8A illustrates a room sealed system.

Fig. 813 illustrates a room open system wherein a first initial flue duct vent into a second terminal flue duct. Fig. 8C illustrates a room open system wherein each heat engine has an independent flue duct.

Detailed Description of the Best Mode for Car!ying Out the Invention

There will now be described by way of example the best mode contemplated by the inventors for carrying out the invention. In the following description numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the present invention.

The inventors have realized the potential use and advantages of incorporating a plurality of heat engine units of the type known in the prior art into a single modular boiler apparatus unit having a small unit footprint such that the module does not take up excessive floor space. The inventors have further realized the advantages gained over the prior art by incorporating into such a module header supply feed-pipes which may be connected to adjacent modules lo of the same type such that several boiler apparatus module units may be placed adjacent each other and thus a required thermal output obtained by connecting together a suitable number of units.

Fig. 1 illustrates a first embodiment of the present invention in external is perspective view showing a single boiler apparatus unit having an external case 101 with control panel 103. Also visible on the exterior surface of the unit are flanges 102, for connecting the header supply between adjacent boiler units when more than one boiler unit is connected together to produce an increased thermal output.

Fig. 2 illustrates in external perspective view the external appearance of a bank of boiler apparatus units made up of single modules connected together by means of flanges 102, such that a continuous interconnected header supply is maintained between the boiler apparatus units such that water is fed into one end of the module unit and may return at a second end. Such a bank of boiler apparatus units may further take advantage of a single gas supply to the heat engines within each unit by use of a gas manifold which forms a common connection to the appliance.

The arrangement of boilers as shown in Fig. 2 provides a compact means of stohng the heat engines contained therein whilst providing an easy-toinstall -g- system which may be tailored to the required heating needs for producing a required thermal output. Internal gas and water supply, the latter being provided by headers 102 provide simple installation wherein the flanges of the last boiler unit in a lined arrangement as shown in Fig. 2 may be blanked off.

Fig. 3 illustrates an alternative arrangement of boiler apparatus units wherein all units are arranged in a parallelepiped shape. Flanges 102 provide for connection of header supplies whilst the arrangement optimizes use of floor space. Additional boiler units may be added.

Fig. 4 illustrates a first specific embodiment of the present invention and illustrates the boiler apparatus unit illustrated in Fig. 1 with the external cover 101 removed. The boiler unit is comprised of a chassis 401 having a first end and a second end. At said first end attached to said chassis is a foot portion 402 is configured such that the boiler apparatus unit may be supported and if necessary secured to a floor surface and thus occupy a minimal floor space or footprint.

The footprint occupied being ideally no more than 0.25 M2 and preferably 0.22 m 2. A bracket 407 may be used in association with an appropriate fastening means, e.g. screw fastening means to secure the foot portion 402 and therefore chassis 401 and the accompanying parts and fittings supported by chassis 401 to an appropriate floor surface.

Chassis 401 supports the parts and fittings forming the boiler apparatus unit module. Namely, these include two heat engines 403, each heat engine being one of a known type, and typically either a non-condensing type heat engine having a cast iron heat exchanger or alternatively a condensing type heat engine having a cast aluminum heat exchanger. Additional parts may include individual pumps 406 for each heat engine 403. A plurality of heat engines may be included in a single boiler apparatus unit, however typically two such heat engines are supported within a single boiler apparatus unit. Each heat engine receives a supply of water from an integral header via flange 102. In an arrangement of heat engines as shown in Fig. 4 wherein one heat engine is aligned vertically above the second heat engine then a header feed 102 is located mid-way between the two heat engines such that a pipe 601 having associated valves and taps provides via a network of pipes and tubes providing a feed and return means for water flow into and out of a heat engine 403. A second header is present immediately adjacent and vertically above the upper heat engine 403 which similarly provides a water transfer pathway to the upper heat engine with its own taps and valves and network of piping to facilitate and accommodate water supply/return.

Fig. 4 illustrates the lower heat engine 403 to have an outlet flue 404 at an upper portion of heat engine 403 for outlet of gases via a flue duct 405.

Fig. 5 further illustrates the boiler apparatus unit shown in Fig. 4 from a side- on view and illustrates outlet flue 404 from lower heat engine 403. Outlet flue 404 is connected to a flue duct 405 by a ducting running behind the upper heat engine 403 within chassis 401.

Fig. 6 further illustrates the ducting 602 which transfers outlet gas from lower heat engine 403 to flue duct 405. Fig. 6 further illustrates header pipe 601 between header pipe connection 102 formed by flanges which are thus interconnectable between adjacent boiler units.

Fig. 7 further illustrates outlet flue 602 running within chassis 401.

In a first specific embodiment of the present invention there is provided a boiler apparatus unit as illustrated in Figs. 1 and 4-7 herein. The boiler apparatus unit comprises two heat engines 403 located within and supported by a chassis 401. The two heat engines 403 are aligned vertically above one another such that the unit may be supported by footplate 402 secured to a floor surface by brackets 407, or alternatively may be wall-mounted by fixing chassis 401 to a wall surface. This may be combined with support at a floor surface 402.

The heat engines 403 are of a known type in the prior art. In a first embodiment each heat engine is a known Suprima 120 heat engine known to be used in prior art boilers. These are known to be manufactured to produce a combined output of 50, 60 or 70 kW. The Suprima 120 includes a cast iron heat exchange unit of low weight, yet high thermal output and thus is suitable for incorporation into a boiler apparatus unit as described in the first embodiment. It lo is the lightweight nature of such a cast iron heat exchanger that makes this possible, the reasons for this being two-fold. Firstly, the boiler apparatus unit 101 has a small unit footprint, typically of 0.25 M2, when stood in a vertical manner and the use of the Suprima 120 having a large thermal output with small weight and size ratio is ideal for such a purpose. Secondly, the comparatively low weight of the Suprima 120 cast iron heat exchanger means that it is possible to support one heat engine 403 above a second heat engine 403 in vertical alignment in a single boiler apparatus unit while still making the unit manageable for rapid installation due to the fact that the total weight of the unit is not excessive. The Suprima 120 is a non-condensing type heat engine and thus the first specific embodiment is a non-condensing type boiler apparatus unit.

The use of two known prior art Suprima 120 heat engines using standard fittings makes the manufacture of a boiler apparatus unit 101 relatively simple. The boiler apparatus unit 101 is designed for rapid installation on demand with simple connection to gas supply via a gas manifold as well as ease of connection for header water supply and return and for flue ducting in order to vent outlet gases. The arrangement of heat engines and associated parts and fittings within a single chassis 401 housing means that a single apparatus unit may be incorporated to achieve twice the normal heat engine output with simple 30 connections to gas supply, water header feed and return, and flue ducting.

In a second specific embodiment of the present invention there is a boiler apparatus unit 101 as shown in Figs. 1, 4-7 herein and substantially as described above. The second embodiment differs to the first embodiment in that heat engines 403 comprise cast aluminum heat exchanger being of a condensing type and thus the overall boiler apparatus unit is a condensing type boiler. As with the first specific embodiment, the use of cast aluminum heat exchange units provides a lightweight solution for the incorporation of a plurality of heat engines within a single apparatus by vertical alignment and therefore reducing floor space footprints of the entire unit saving space and creating a large thermal output by lo use of lightweight heat engines 403 capable of producing up to 70 kW thermal output in tandem.

Alternative embodiments to the vertical alignment of heat engines 403 in a single boiler apparatus unit 101 comprise those arrangements described below in embodiments 3 and 4 herein.

In a third specific embodiment of the present invention there is a boiler apparatus unit comprising two or more heat engines 403 as described above wherein heat engines 403 are aligned in a horizontally adjacent manner such that the boiler apparatus unit forms a box which may be supported on a floor surface by a long chassis length compared to the vertical height of the unit. Although this type of unit has a larger footprint than that described in the first specific embodiment of the present invention it is suitable for vertical stacking of boiler units hence providing the capability of a decreased overall footprint if a large 2s number of boiler apparatus units are stacked together.

In a fourth specific embodiment of the present invention there is provided a boiler apparatus unit having two heat engines 403 wherein each heat engine is arranged in a back-to-back manner and may be secured together by a suitable bracket or other fastening means. This type of unit is housed in a chassis forming a box shaped unit which is more suitable for use in a freestanding area than in a wall-mounted situation, although it does not exclude the possibility of this type of unit being wall-mounted.

Any of the embodiments 1 to 4 described herein above may be incorporated within a boiler apparatus unit having a single main gas supply which may be via a gas manifold unit and integral header water supply and return feeds. This provides for the minimum of installation requirements whereby to install the unit the gas supply needs to be connected to an appropriate flange or manifold on the unit and water supply and return should be connected via supply header flanges lo 102. Further, the flue duct 405 provides for a single connection to vent outlet gases via a flue duct or where a room sealed system is in operation to provide a pathway for both inlet and outlet gases.

The first specific embodiment will now be described in terms of the flow of water to feed and return headers and in terms of the flow of inlet and outlet gases via flue ducting 405 and associated ducts 404, 602. The features described herein for transmission of gas, water and inlet and outlet gases may equally be applied to any of embodiments 2 - 7 as described herein.

The first specific embodiment overcomes the main problem with mounting two boilers vertically together which is that of achieving a common air and flue connection. This problem has been overcome by use of prior art heat engines

403 having existing flue duct elbows 404 for transmission of gases either into or out of heat engine 403. Ducts 404 may comprise either a 60 or 80 mm duct arrangement which continues to run behind upper heat engine 403 via a continuous duct through chassis 401 joining a flue outlet outletting from an upper portion of upper heat engine 403 and thus entering a flue duct 405. Flue duct 405 thus provides a first specific flue embodiment wherein a common flue system is provided. A common flue system being wherein the outlet gases from both heat engines 403 within a single boiler apparatus unit are channeled into a single common flue duct 405 which may then be attached to suitable ducting transferring outlet gases to a terminal portion. A terminal portion may be provided by a suitable outlet at an exterior portion of the building within which boiler unit 101 is maintained. This first specific flue embodiment is illustrated in Fig. 8b which shows heat engines 403 each having first flue ducts 404 connected to a second flue duct 405 wherein outlet gases from heat engines 403 are channeled into a common flue 405 which provides for transfer of outlet gases to a terminal portion located at an exterior site on the building within which boiler apparatus unit 101 is maintained.

is A second flue embodiment is illustrated in Fig. 8A wherein each heat engine 403 has a first initial flue duct 404 connected to secondary flue ducting for transfer of exhaust gases to a terminal portion. This second specific flue embodiment therefore provides two separate pathways for outlet gases to be transferred from heat engine 403 to an external point. This type of arrangement is compatible with a room sealed boiler apparatus unit wherein flue ducting 404 comprises 100 mm ducting having an internal ducting pathway separate to the external duct pathway. Said internal duct pathway providing a pathway for inlet of air to heat engines 403. This system being compatible with a balanced flue arrangement.

Fig. 8C shows a third specific flue embodiment wherein each heat engine 403 has a separate duct pathway 404 providing a flue for transmission of outlet gases to a terminal portion there being a separate terminal portion for each flue duct 404.

The first and third specific flue embodiments as illustrated schematically in Figs. 813 and 8C respectively are compatible with a room open system wherein heat engines 403 draw in air from the surrounding atmosphere within a room in which boiler apparatus unit 101 is maintained thus flue ducting 404 may be of 3o 80mm diameter ducting.

The boiler apparatus unit as described in the first specific embodiment with reference to Figs. 1, 4-7 herein is compatible with any of the 3 specific flue embodiments described above with reference to Fig. 8A, 813 and 8C respectively. In manufacturing boiler apparatus unit 101 a standard unit having flue duct s elbows 404 is provided. On determination of the suitable type of flue system to be used in the specific circumstances of use of the boiler apparatus unit, then the boiler apparatus unit may be tailored to be compatible with any of the 3 specific flue embodiments as illustrated in Fig. 8 herein and thus the boiler apparatus unit may be supplied with a kit of parts consisting of flue ducting, joints for flue ducting lo and appropriate terminal portions for producing any 1 of the 3 specific flue embodiments described above and with respect to Fig. 8 herein. Thus, boiler apparatus unit 101 is adaptable for use in a room open system wherein combustion gases are drawn into heat engines 403 from the surrounding atmosphere. This system being compatible with either a common flue as in Fig.

813 or a non-common flue as in the Fig. 8A arrangement. These arrangements providing versatility of use of boiler apparatus units 101 in order that the requirements of The Clean Air Act 1956 can be met with respect to the location of venting of outlet gases from flue ducting extending from boiler units. Boiler apparatus unit 101 is further compatible with a room sealed arrangement wherein combustion gases are drawn down a duct pathway in a flue duct 404, outlet gases thus being passed within an internal duct pathway and vented at a terminal portion. Such an arrangement is compatible with a balanced flue system.

Boiler apparatus units as described in embodiments 1-4 above in combination with any one of flue embodiments 1-3 as described above thus provide a versatile boiler apparatus unit having lightweight heat engines capable of a large thermal output. The boiler apparatus unit 101 being simple to install with single gas supply connections and integral header feed and return water supply and associated parts and fittings. The boiler apparatus unit 101 further having a small footprint, in particular a small footprint in the region of 0.25 M2 is provided by embodiments 1 and 2 of the boiler apparatus unit. Thus, a large thermal output by be provided with minimum space taken up.

Boiler apparatus unit 101 may be freestanding, i.e. it may be selfsupporting s on a floor surface, or may be wall-mounted, i.e. aligned against a wall but further being floor supported by floorplate 402.

The versatility of boiler apparatus unit 101 as described in embodiments 102 above is further demonstrated by embodiments 5 and 6 as described below.

In the following description particular emphasis is drawn to the internalheader of the water supply and return means provided by pipework 601, valves and associated parts and fittings, as well as flange connections 102. By incorporating internal header units having flanges 102 at an external side portion of chassis 401 or boiler apparatus unit cover 101 then boiler apparatus unit 101 may be used in a modular arrangement by connecting headers 102 together between adjacent units and thus providing a bank of boiler apparatus units providing a required thermal output.

In particular, specific embodiment 5 of the present invention as illustrated in Fig. 2 shows a bank of four boiler apparatus units wherein headers are connected together by flanges 102 to provide a continuous water supply feed and return to the boiler apparatus unit. A similar arrangement may be provided including a gas manifold for a single central gas supply. Each of the boiler apparatus units included in such a bank of 4 units may be arranged with any of the specific flue embodiments 1-3 herein. Thus, the arrangement may take advantage of a room sealed system which may further incorporate a balanced flue as in Fig. 8A or each heat engine within each boiler apparatus may have its own flue ducting transferring gases to a terminal portion for outlet of exhaust gas wherein the system is a room open system taking air for combustion within heat engines 403 from the surrounding atmosphere. More commonly however, in a modular arrangement as illustrated in Fig. 2 having a bank of boiler apparatus units the arrangement as illustrated in Fig. 8B and described in specific flue embodiment 1 above is anticipated to be the most common use. Here, each boiler apparatus unit is of the type described in boiler apparatus unit embodiments 1 or 2 herein having either a cast iron heat exchange element within each heat engine 403, or a cast aluminum heat exchange element each heat engine 403 thereby being either a non-condensing or condensing type heat engine respectively. Considering the use of specific flue embodiment 1 wherein a common flue system is used as illustrated in Fig. 8B. Combustion gases are drawn into heat engine 403 from the surrounding atmosphere in a room open type system, outlet gases from each heat engine are transferred by ducting 404 preferably by a suitable elbow and are then channeled by a ducting to a common joint preferably a T-joint above the upper heat engine 403 thus outlet gases from both heat engines 403 are transferred to a common ducting 405. Each of the common ductings 405 may be further channeled into a larger central duct receiving outlet gases from common duct 405 of each of the boiler apparatus units comprising the bank of 4 units as shown in Fig. 2. This larger central flue duct then provides a pathway for outlet of gases to a terminal portion.

In a fifth specific embodiment of the present invention as illustrated in Fig. 2 herein boiler apparatus unit 101 forms a modular unit wherein an additional boiler apparatus unit may be fitted into the system by placing a further unit adjacent to the existing bank of units and connecting header supplies via flanges 102 and connecting means eg pipework and fittings, and by further connecting flue duct 405 to the larger central flue duct described above. Thus, in theory the number of boiler apparatus units 101 incorporated into such a bank of units is without limit and may thus be tailored to provide the required thermal output. Thus an easyto-instail and easy-to-modulate system for providing a thermal output for heating of water may be rapidly provided using a minimal floor space provided by the small footprint of boiler apparatus unit 101. The practical limit placed on the number of boiler apparatus units in a single bank is reliant upon a number of features:

b.

a. Gas supply - i.e. the size of supply and associated gas manifolds required. The diameter of header pipe 601 which governs the amount of water which may be heated by heat engines 403 and thus practically limits the maximum thermal output. Limits are further placed by the size of flue ducting 404 and 405 which may be required to meet the relevant British standards.

All of the above features are thus capable of variation in size to meet a required demand.

The use of standard headers for water supply and return means that no additional headers are needed on installation and installation becomes simple and quick. This means that the installer has no significant additional material costs on installation. Flanges 102 are mounted just outside the appliance casing 101 enabling spanner access such that installation is rapid and simple when connection of headers is required in a modular unit as illustrated in Fig. 2. For a multiple boiler unit system as illustrated in Fig. 2 where a low level discharge is required, a fan-diluted flue system may be incorporated to discharge products at less than'% C02.

A sixth specific embodiment of the present invention shows a further application of an individual boiler apparatus unit 101 as a module in a bank of boiler apparatus units as described in the fifth specific embodiment herein. This further arrangement is illustrated in Fig. 3 wherein boiler apparatus units are placed adjacent each other to form a box shape which may be freestanding within a central space of a room. Interconnecting headers for water supply and return and interconnecting gas supplies via a gas manifold are provided and a common flue 405 from each individual unit may be transferred by suitable ducting to a larger central flue for outlet of gases. As with the fifth specific embodiment this type of arrangement may be used in a room open or room sealed system as required the appropriate flue embodiment being incorporated on installation.

In both the fifth and sixth specific embodiments of the present invention a four bank boiler apparatus unit system has the capacity to produce a 280 kW output. The output is dependent on the specific heat engines used and figures are calculated on the use of the prior art Suprima 120 heat engine.

The above embodiments have described a boiler apparatus unit having two lo heat engines suitable for use as a module in a bank of boiler apparatus units which may be tailored to produce a required thermal output. There is no limit to the number of heat engines used within a single boiler apparatus unit or to their size, weight and thermal output. To accommodate larger heat engines, larger diameter pipework for header feed water supply and return may be incorporated and larger diameter flue ducting may further be incorporated.

A final variation of the present invention is encompassed within a seventh specific embodiment of the present invention. This describes a boiler apparatus unit substantially as herein described in first and second specific embodiments herein and suitable for use and application with any of the boiler apparatus unit embodiments described herein in combination with any of the three specific flue embodiments described herein. The seventh specific embodiment incorporates a pressure-sensor within flue ducting 404 or flue-ducting 405 or even within a larger central flue ducting described for use in a common flue situation where a bank of 2s boiler apparatus units are used as illustrated in Figs. 2 and 3 herein. Such a pressure sensor can detect changes in pressure within flue ducting 405 and 404 or other associated flue ducts and thus detect a blockage or partial blockage of a flue duct resulting in a change in outlet gas pressure. On detection of a finite change in pressure, the pressure sensor acts in accordance with associated circuitry to deactivate one or more of the heat engines 403. Deactivation includes turning off one of the heat engines 403, or simply turning down the thermal output of one or more heat engines 403 such that the amount of outlet gas is reduced and thus the effect of the flue blockage is not to affect the performance of the boiler apparatus unit or contravene The Clean Air Act 1956. Further on sensing a change in pressure an indication on control panel 103 may be shown e.g. a light may be lit or a buzzer may be sounded whereby a boiler apparatus unit operator may be informed of the blockage and action may be taken to remove the blockage.

Claims

Clairns:

1. A boiler apparatus unit comprising:

a chassis; having a first end and second end and supporting two or more heat engines; wherein said heat engines comprise cast metal heat exchange elements.

2. Boiler apparatus as claimed in claim 1, wherein said cast metal is cast iron and said boiler apparatus is a non-condensing boiler apparatus.

3. Boiler apparatus as claimed in claim 1, wherein said cast metal is cast aluminium and said boiler apparatus is a condensing boiler apparatus.

is

4 Boiler apparatus as claimed in claim 1, 2 or 3, configured for use as a free standing or wall mounted unit.

5. Boiler apparatus as claimed in any of claims 1 to 4, wherein said heat engines are vertically aligned and said boiler apparatus unit has a unit footprint of, or smaller than 0.4 M2.

6. Boiler apparatus as claimed in any previous claim wherein each heat engine has an integral header supply taken from a header feed wherein said header feed may be connected to an adjacent boiler apparatus by connecting means thus forming a continuous header feed between adjacent boiler apparatus.

7. More than one boiler apparatus as claimed in claim 6, placed adjacent to each other and having a header feed interconnected by said connecting means between said boiler apparatus.

8. A plurality of boiler apparatus as claimed in claim 7, wherein said boiler apparatus operate in concert to produce a required thermal output.

9. Boiler apparatus as claimed in any previous claim, wherein said heat engines are configurable for use with either a room sealed flue system or a room open flue system.

10. Boiler apparatus as claimed in claim 9, wherein said heat engines lo share a common flue.

11. Boiler apparatus as claimed in claim 9, wherein said room sealed flue system is a balanced flue system.

12. Boiler apparatus as claimed in claim 9 or 11, wherein said room sealed flue system comprises separate flue ducts extending from each of said heat engines each to a separate terminal portion.

13. Boiler apparatus as claimed in claim 12, wherein said flue ducts comprise an inner and outer pathway for a transmission of inlet and outlet gasses to and from said heat engines by means of a balanced flue system.

14. Boiler apparatus as claimed in claim 9, wherein said room open flue system comprises first flue ducts extending from each of said heat engines, said first flue ducts joining a second flue duct, said second flue duct providing a pathway for transmission of outlet gasses to a terminal portion.

15. Boiler apparatus as claimed in claim 9, wherein said room open flue system comprises a flue duct extending from each of said heat engines, each of said flue ducts providing a pathway for transmission of outlet gasses to an independent terminal portion.

16. Boiler apparatus as claimed in any of claims 12 to 15 wherein any of said flue ducts further comprises a pressure sensor arrangement operable to deactivate one or more of said heat engines in response to a change in pressure in said flue ducts.

17. Boiler apparatus as claimed in claim 1, with reference to Figs. 1, 4, 5, 6 and 7 herein.

18. A method of installation of a boiler apparatus unit as claimed in any previous claim comprising the steps of:

connecting said boiler apparatus to a gas supply; is connecting said boiler apparatus to a water supply by a header feed flange; connecting flue ducts to further flue ducting for transfer of outlet gases.

19. A method of installing a plurality of boiler apparatus as claimed in claim 18, further comprising the steps of:

placing more than one boiler apparatus as claimed in any of claims 1-18 adjacent each other; interconnecting adjacent boiler apparatus water supplies by interconnecting header feeds.

20. A method as claimed in claim 19 further comprising the step of connecting flue ducts to a central flue duct system.