GB2177492A - Gas-fired heating appliance - Google Patents

Abstract

A gas-fired heating appliance, having a number of burners and an inlet manifold, comprises a pair of plates (10, 11) which are connected together in an overlying relationship, at least one of said plates (10) being formed in that surface which is adjacent to the other plate (11) with a plurality of grooves (9,23,24,25,26) which will form,when the plates (10,11) are connected together, passages for conducting gaseous fuel to said burners, the inlet manifold also being connected to valve means for selectively directing said gaseous fuel to whichever burner or burners as are required by the user to be ignited. The plate 10 may be formed as a metal die casting. <IMAGE>

Description

SPECIFICATION Gas-fired heating appliance This invention relates to a gas-fired heating appliance and, although it is envisaged that such an appliance may be in the form of apparatus intended for use in carrying out cooking or other heat treatment operations, the invention is primarily concerned with a gas-fired heating appliance which comprises a space-heating apparatus, especially apparatus which is used for domestic space heating.

It is common practice, in known gas-fired heating appliances, to provide an inlet manifold system for delivering gaseous fuel to the burner or burners which includes pipework providing conduits along which the gaseous fuel can flow. Such pipework is frequently relatively expensive to manufacture and fit and these disadvantages are especially apparent in cases where the gas-fired heating appliance is provided with more than one burner. It is therefore an object of the present invention to provide a gas-fired heating appliance having an inlet manifold which substantially reduces or entirely avoids the need for providing pipework as aforesaid.

In accordance with the present invention there is provided a gas-fired heating appliance having a number of burners and an inlet manifold which comprises a pair of plates which are connected together in an overlying relationship, at least one of said plates being formed in that surface which is adjacent to the other plate with a plurality of grooves which will form, when the plates are connected together, passages for conducting gaseous fuel to said burners, the inlet manifold also being connected to valve means for selectively directing said gaseous fuel to whichever burner or burners as are required by the user to be ignited.

Conveniently, only one of said plates are formed with grooves as aforesaid, such plates being preferably formed as a metallic die casting.

The inlet manifold is also preferably provided with a gas pressure regulating device and a flame failure gas cut-off valve.

The invention will now be more particularly described with reference to the accompanying drawing which is an "exploded" perspective view of an inlet manifold which can be incorporated in one example of a gas-fired heating appliance in accordance with the invention.

Referring now to the drawing there is shown therein an inlet manifold which can be used in one example of a gas-fired appliance constructed in accordance with the invention. The appliance itself is provided with a number of burners - for example three (not shown). Each of said burners may be of the surface combustion kind and there is also provided a pilot burner with which is associated a flame failure device in the form of a thermally sensitive element which is connected to a flame failure gas cut-off valve, the arrangement being such that so long as a normal pilot flame issues from the pilot burner said thermally sensitive element will be heated to produce an electric current which maintains the aforesaid flame failure gas cut-off valve in an open condition, said valve comprising an electro-magnetically actuated solenoid valve.

The aforesaid manifold comprises a pair of plates namely plate 10 and plate 11. At least one, but preferably only one, of said plates (namely plate 10 in the example shown) is formed in one surface with a plurality of grooves, said plate 10 being conveniently formed as a metallic die casting. The other plate 11 is secured to the plate 10 in an overlying relationship, the connection between said plates being conveniently made by means of screws such as screw 12 which extend respectively through plain apertures formed in the plate 10 and screw threaded holes such as hole 13 formed in the upper plate 11. There is also conveniently provided between said plates an anaerobic gasket or sealant which is placed around the edges of the plates between the lower surface of the upper plate 11 and the upper surface of the lower plate 10.Alternatively, a sheet of gasket material (such as rubber-backed cork) may be used.

As seen in the drawing the lower plate 10 is formed with a plurality of downwardly extending integral housings 14, 15 and 16 whereas the upper plate 11 which may also be formed as a metallic die casting is provided with an integral upwardly projecting housing 17. Said upper plate 11 is also formed at positions remote from its edge with a plurality of other apertures but the underside of said plate 11 is of substantially plane configuration.

The integral housing 17 serves to contain the upper part of a gas pressure regulating device comprising a disc 18 a spring 19 and a further disc and diaphragm assembly 20, whilst the housing 14 serves to contain a spring loaded ball valve 21 which is seen through an aperture 22 formed in the upper end of said housing 14. In use a supply of gaseous fuel is connected to said housing 14 and the pressure exerted by said spring 19 can be adjusted by an adjusting screw 23 in order to regulate the pressure of gas entering said housing 14.

From the upper part of said housing 14 gas can pass along one of the aforesaid grooves namely groove 23 formed in the upper surface of the plate 10 it being understood that the upper part of said groove 23 will be closed by the lower surface of the plate 11, thus forming a passage in the inlet manifold through which the incoming gas supply can flow. Said incoming gas can then flow into the aforesaid housing 16 which in fact contains the afore-mentioned electro-magnetically operated cutoff valve and provided said valve is in an open condition (the pilot burner then producing a normal pilot flame) gas can then flow upwardly through the inlet manifold to valve means which in use will be mounted above said plate 11 and which can be rotated in order to selectively direct the gaseous fuel to one or more of the aforesaid burners.Said valve means are not illustrated in the accompanying drawing but are more particularly described in our co-pending Patent Application No.

of even date. Suffice it to say however that by setting said valve means gas can be directed through one or more of further passages formed in the inlet manifold, such passages being provided by grooves 9, 24, 25, and 26 which are also closed on their upper sides by the lower surface of plate 11.

The groove 9 is arranged to conduct gas to the housing 15 and thence on to the pilot. Such pilot will in use be ignited by an ignition device such as a piezo-electric device (not shown) so that this pilot will be the first to be lit when the appliance is turned on. The other grooves 24, 25 and 26 which, together with the adjacent parts of the lower surface of the upper plate 11 form further passages, lead respectively (in this example) to the centre burner and the two outer burners in turn. The jets of said burners will be secured in screw threaded holes 27, 28 and 29 formed in the upper plate 11.

The aforesaid valve means when rotated will permit gas to flow along the appropriate groove 24, 25 or 26 respectively, the centre burner being first to ignite and then the two outer burners in turn.

The alternative burner combinations are thus pilot only; pilot plus centre burner; pilot plus centre plus one outer burner; and finally pilot plus centre plus two outer burners.

The aforesaid integral housing 15 contains the aforementioned pilot burner which in use will heat the thermally sensitive element controlling the operation of the cut-off valve contained in said housing 16.

Thus the inlet manifold as above described is very simply formed from a pair of plates which are secured together and which, in combination with the aforesaid surface combustion burner elements form a reiatively inexpensive but effective combination of inlet manifold and burners which does not involve the provision 06 external pipework.

Claims (6)

1. A gas-fired heating appliance having a number of burners and an inlet manifold which comprises a pair of plates which are connected together in an overlying relationship, at least one of said plates being formed in that surface which is adjacent to the other plate with a plurality of grooves which will form, when the plates are connected together, passages for conducting gaseous fuel to said burners, the inlet manifold also being connected to valve means for selectively directing said gaseous fuel to whichever burner or burners as are required by the user to be ignited.

2. An appliance as claimed in Claim 1, wherein only one of said plates are formed with grooves as aforesaid.

3. An appliance as claimed in Claim 1 or 2, wherein each of said plates is formed as a metallic die casting.

4. An appliance as claimed in any preceding claim, wherein the inlet manifold is provided with a gas pressure regulating device.

5. An appliance as claimed in any preceding claim, wherein the inlet manifold is provided with a flame failure gas cut-off valve.

6. An appliance as claimed in Claim 1, which is substantially as herein described with reference to the accompanying drawings.