[0001] Combustion devices for heating water in central-heating systems can nowadays be constructed
very compactly, for instance for heating an apartment in a larger building. Such compact
combustion devices can then be connected to for instance a collective supply conduit
for supply of air and/or a collective discharge for discharge of combustion gases.
[0002] As well as compactness, efficiency at full load and/or at relatively low load is
also of increasing importance in the context of increasing environmental requirements
and fuel costs. It has further been found in practice that noise nuisance can occur
at relatively low loads of compact combustion devices, for instance because of the
eigenfrequency of particular spaces in such a compact combustion device.
[0003] The present invention has for its object to obviate one or more of the above stated
problems and provides a device for combusting fuel and oxidizing agent, for instance
for space heating, wherein the device comprises:
- a burner;
- supply means for supplying the fuel and the oxidizing agent to the burner; and
- discharge means for discharging combustion gases from the burner, wherein supply of
fuel and/or oxidizing agent, and/or discharge of the combustion gases takes place
in forced manner, and wherein a non-return valve is arranged in either the supply
means or the discharge means.
[0004] When the burner is connected to a collective air conduit in the switched-off situation,
the closing means prevent relatively cold air entering the interior thereof, which
may reduce efficiency. In the case of connection to a collective discharge conduit
for the combustion gases, the closing means prevent the possibility of combustion
gases from another combustion device being drawn into the interior of the boiler,
which is likewise undesirable.
[0005] In a preferred embodiment of the device according to the present invention, wherein
the closing means are formed by a valve which can move freely up and downward between
baffle-like members forming part of mixing means, it has further been found that the
noise nuisance is prevented, probably because the resistance in the air path is increased.
[0006] In order to prevent an undesired whine of relatively high frequency, the up and downward
movable disc-like valve is preferably arranged with some clearance round a central
shaft.
[0007] Further advantages, features and details of the present invention will be elucidated
on the basis of the following description with reference to the annexed figure, in
which a preferred embodiment of a device according to the present invention is shown.
[0008] On the underside of a device 10 air is supplied as according to arrow A via a fan
11, while the gas for combusting is supplied under some pressure via connection 12
as according to arrow B. Arranged in a mixing space 8 are disc-shaped baffles 13,
14, 15 and 16, in which passage openings for the gas and the air are provided which
are successively offset relative to each other for mixing the gas and the air in efficient
manner, as indicated schematically by the arrows. The mixture of air and gas is subsequently
carried into the interior of burner 17 and burns in the annular space 18 to heat the
helical pipe 19 which in the present case comprises an inner pipe 20 and an outer
pipe 21. The combustion gases are urged downward and discharged via a discharge conduit
22 for the combustion gases.
[0009] Inner pipe 20 and outer pipe 21 are connected to a central-heating system and the
circuit for hot water, further details of which are described in the Netherlands patent
application 1004410, the content of which must be deemed as interpolated herein. Tap
water for heating is fed for instance as according to arrow C and drained as according
to arrow D, while water for heating for the central-heating system is fed for instance
as according to arrow E and drained as according to arrow F.
[0010] A substantially disc-shaped valve 30 is arranged between mixing baffles 14 and 15
for free movement with some clearance round a central shaft 31. If device 10 is switched
off and combustion is stopped, fan 11 will also be switched off, whereby disc 30 drops
due to its own weight onto disc 15 and closes the openings therein. The air path through
the combustion device is hereby closed and relatively cold air and/or combustion gases
are prevented from being able to enter the interior thereof.
[0011] When the central-heating boiler is switched on again and fan 11 activated, the closing
disc 30 is raised slightly by the air flow brought about by the fan. At switch-on
as much hot air and/or combustion gas as possible is therefore still situated in the
space, which reduces standstill losses.
[0012] The present invention is not limited to the above described preferred embodiment;
the rights sought therefor are defined by the following claims, within the scope of
which many modifications can be envisaged.
1. Device for combusting fuel and oxidizing agents, for instance for space heating, wherein
the device comprises:
- a burner;
- supply means for supplying the fuel and the oxidizing agent to the burner; and
- discharge means for discharging combustion gases from the burner, wherein supply
of fuel and/or oxidizing agent, and/or discharge of the combustion gases takes place
in forced manner, and wherein a non-return valve is arranged in either the supply
means or the discharge means.
2. Device as claimed in claim 1, wherein the supply means comprise mixing means for mixing
the fuel and the oxidizing agent.
3. Device as claimed in claim 2, wherein the mixing means comprise two or more baffle-like
members in which holes are arranged.
4. Device as claimed in claim 1, 2 or 3, wherein the supply means comprise a fan for
supplying air at some overpressure.
5. Device as claimed in claim 1, 2, 3 or 4, wherein the closing means comprise an up
and downward movable disc in the air path.
6. Device as claimed in claim 3, 4 or 5, wherein the disc is provided centrally with
an opening for arranging thereof with the necessary clearance on a central shaft.
7. Device as claimed in claim 5 or 6, wherein in the rest position the disc closes the
opening in one of the baffle-like members.