GB2060146A - Improvements in or relating to water heating boiler installations - Google Patents

Abstract

A multiple water heating boiler installation comprises boiler modules 1, 2, 3 each having a heat exchanger through which the water to be heated flows, a burner disposed to heat the water flowing through the heat exchanger, and a separately formed and selected cross-section flue 4 coupled to a flue outlet from the burner. The flues 4 are adapted to be disposed one above the other with the cross-section of the or each flue above the bottom flue being larger than the cross-section of the flue immediately below it. <IMAGE>

Description

SPECIFICATION Improvements in or relating to water heating boiler installations This invention relates to water heating boiler installations, more especially for central-heating and/or indirect hot water supply, and is concerned with the provision of a multiple boiler installation of improved efficiency. The installation is preferably a low water content installation.

According to the invention there is provided a multiple water heating boiler installation comprising a plurality of boiler modules each having a heat exchanger through which the water to be heated flows, a burner disposed to heat the water flowing through the heat exchanger, and a separately formed and selected cross-section flue adapted to be coupled to a flue outlet from the burner, the flues being adapted to be disposed one above the other with the cross-section of the or each flue above the bottom flue being larger than the cross-section of the flue immediately below it.

Thus the cross-section of the flue associated with each module will be selected in accordance with the position of the flue in the vertical stack of flues formed when the installation is assembled, and this stack will serve to discharge the flue gases from each of the modules coupled to the stack.

The modular construction of the boiler installation is particularly convenient from the point of view of manufacture since it enables a number of identical boiler modules of the same capacity, say 60 Kw, to be combined together to provide a wide range of installations of different capacities. Having installed the number of modules appropriate to an installation, all that is necessary is to select a flue for each module appropriate to the position of the module in the installation and to couple each flue to the flue outlet of the appropriate module and to interconnect the various flues. Such a construction also renders modification of an installation to increase its capacity particularly simple.

The installation may comprise a plurality of boiler modules stacked one on top of the other, and it will be appreciated that such an arrangement permits the capacity of the installation to be increased, by adding a further boiler module to the stack, without increasing the required floor area.

In a preferred embodiment each boiler module is provided with a downdraught diverter for attachment to the flue outlet of the module, and the corresponding flue is in the form of a separately formed tube of selected cross-section for attachment to the top of the downdraught diverter in register with an aperture of corresponding cross-section in the downdraught diverter. Each downdraught diverter preferably has an open bottom so that, if a downdraught is created in the vicinity of the flue outlet, the products of combustion are carried away from the boiler module so that combustion is not effected and carbon monoxide is not produced to a significant extent. The tubular flues may be of circular cross-section and the downdraught diverters may be of rectangular cross-section, the latter being provided with means, for example flanges, along one side for fitting within the flue outlets.The flue outlets of all the modules can be of the same dimensions so that each downdraught diverter and its associated flue can be fitted to any module. Both the downdraught diverters and the flues are made of mild steel, for example.

The invention also provides a boiler installation having a water space in at least one region thereof delimited by two mutually parallel plates, at least one of which is deformed towards the other plate in a plurality of regions distributed over the plate and is fixed to the other plate in these regions, preferably by means of arc welding. Both plates may be deformed at corresponding locations, the deformed regions of each plate forming dimples which contact the dimples in the other plate at points half way between the two plates.

The invention also provides a boiler installation having a burner in a lower region thereof and a row of mutually parallel water-carrying pipes inclined to the horizontal in an upper region thereof. Preferably the arrangement is such that water flows along the pipes from their lower ends to their upper ends in operation of the boiler. The pipes are made of copper and are provided with aluminium fins, for example.

The invention further provides a boiler installation having a heat exchanger through which the water to be heated flows, the heat exchanger including at least one water-carrying pipe having a rode extending along the axis of the pipe. The rod serves to increase the speed of flow of water at the periphery of the pipe and thereby prevents "kettling", i.e. boiling of the water in the vicinity of the periphery to produce steam.

The invention further provides a water heating boiler module having the general shape of a rectangular parallelepiped with a chamfered upper edge provided with instrumentation and an opposite chamfered lower edge provided with an air inlet. The module may be provided with a prefabricated mild steel casing. Such a construction is particularly convenient when a plurality of such modules are to be stacked one on top of the other.

In order that the invention may be more fully understood, a preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of the multiple boiler installation, Figure 2 is a section through a module of the installation, viewed from one side, and Figure 3 is a further section through the module, viewed from the front.

The boiler installation illustrated is a gas-fired, natural draught, open-flued boiler installation having a particularly lower water content. The installation has an atmospheric burner and operates without the use of a fan or other moving parts. The electrical consumption is therefore very low and this feature, allied with the high efficiency of the heat exchanger and the fact that a permanent pilot is not required, results in very low overall energy consumption.

Referring to Figure 1 the installation comprises three boiler modules 1, 2 and 3 stacked one on top of the other each of which is provided with a separately formed tubular flue 4 of circular crosssection. Each flue is coupled to the flue outlet of the associated module by a respective downdraught diverter 5 of rectangular crosssection provided with an annular upstanding flange 6 for aligning the flue with an aperture of corresponding circular cross-section in the top of the downdraught diverter 5. Each downdraught diverter 5 has an open bottom 9 and the flues of the modules 1 and 2 open into the open bottoms 9 of the downdraught diverters of the modules 2 and 3, respectively.Each module is provided with a chamfered upper edge 7 for instrumentation and a chamfered lower edge 8 for an air inlet Referring to Figures 2 and 3, the module 1 comprises a housing structure 10 containing a heat exchanger 12 through which water to be heated flows and a gas burner 14 disposed to heat the water flowing through the heat exchanger 12.

The heat exchanger 12 comprises a row of mutually parallel finned pipes 1 6 in an upper region thereof, each of the pipes 16 being inclined to the horizontal and having an anti-kettling rod 18 extending along the axis thereof.

The heat exchanger 12 also comprises four water spaces 20, each of which is delimited by two mutually parallel plates 22 and 24 provided with deformed regions forming dimples 26 distributed over the plates. The dimples 26 in the plate 22 contact the dimples 26 in the plate 24 and are arc welded thereto. Furthermore a drain socket 28 is provided for draining the water spaces 20.

A cold water inlet 24 is provided in an upper region of one of the water spaces 20 at one end thereof and a hot water outlet 26 is provided in an upper region at the other end thereof, the water spaces 20 being interconnected so as to enable water to flow through all the water spaces 20 between the inlet 24 and the outlet 26.

Furthermore the pipes 16 are connected to the water spaces 20 at either end so as to enable water from the water spaces 20 to pass along the pipes 16. The water connections of the different modules are manifolded together, standard flow and return headers being supplied if required.

The downdraught diverter 5 is attached to the flue outlet 32 by means of flanges 34 provided on the diverter 5 which fit within the outlet 32.

Insulation 30 is provided for minimising loss of heat to the atmosphere.

Claims (13)

1. A multiple water heating boiler installation comprising a plurality of boiler modules each having a heat exchanger through which the water to be heated flows, a burner disposed to heat the water flowing through the heat exchanger, and a separately formed and selected cross-section flue adapted to be coupled to a flue outlet from the burner, the flues being adapted to be disposed one above the other with the cross-section of the or each flue above the bottom flue being larger than the cross-section of the flue immediately below it.

2. A boiler installation according to claim 1, wherein the boiler modules are stacked one on top of the other with the flues being coupled to the flue outlets of the modules and being disposed one above the other.

3. A boiler installation according to claim 1 or 2, wherein each module is provided with a downdraught diverter for attachment to the flue outlet of the module, and the corresponding flue is in the form of a separately formed tube of selected cross-section for attachment to the top of the downdraught diverter in register with an aperture of corresponding cross-section in the downdraught diverter.

4. A boiler installation according to claim 3, wherein each downdraught diverter has an open bottom.

5. A boiler installation according to claim 3 or 4, wherein the tubular flues are of circular crosssection.

6. A boiler installation according to claim 3, 4 or 5, wherein the downdraught diverters are of rectangular cross-section.

7. A boiler installation according to any preceding claim, comprising a plurality of stacks of boiler modules arranged side-by-side, the flues associated with each stack being adapted to be interconnected with the flues of the other stack(s).

8. A boiler installation according to any preceding claim, wherein the heat exchanger of each boiler module includes a water space in at least one region thereof delimited by two mutually parallel plates, at least one of which is deformed towards the other plate in a plurality of regions distributed over the plate and is fixed to the other plate in these regions.

9. A boiler installation according to any preceding claim, wherein the heat exchanger of each boiler module includes a row of mutually parallel water-carrying pipes inclined to the horizontal in an upper region thereof.

10. A water heating boiler installation having a heat exchanger through which the water to be heated flows, the heat exchanger including at least one water-carrying pipe having a rod extending along the axis of the pipe.

11. A water heating boiler module having the general shape of a rectangular parallelepiped with a chamfered upper edge provided with instrumentation and an opposite chamfered lower edge provided with an air inlet.

12. A multiple water heating boiler installation substantially as hereinbefore described with reference to the accompanying drawings.

13. A water heating boiler module substantially as hereinbefore described with reference to the accompanying drawings.