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EP 0 647 819 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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26.01.2000 Bulletin 2000/04 |
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Date of filing: 10.10.1994 |
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International Patent Classification (IPC)7: F24D 5/08 |
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Device for heating enclosed spaces
Gerät für die Heizung von umschlossenen Räumen
Appareil pour chauffer des espaces clos
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Designated Contracting States: |
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AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE |
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Priority: |
11.10.1993 IT TV930092
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Date of publication of application: |
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12.04.1995 Bulletin 1995/15 |
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Proprietor: OFFICINE TERMOTECNICHE FRACCARO O.T.F. S.r.l. |
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31033 Castelfranco Veneto (Treviso) (IT) |
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Inventor: |
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- Fraccaro, Gimmi
I-31033 Castelfranco Veneto (IT)
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Representative: Modiano, Guido, Dr.-Ing. et al |
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Modiano & Associati SpA
Via Meravigli, 16 20123 Milano 20123 Milano (IT) |
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References cited: :
EP-A- 0 079 526 EP-A- 0 509 155 FR-A- 2 339 134
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EP-A- 0 503 489 FR-A- 606 020
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention relates to a device for heating enclosed spaces, such as aircraft
hangars, theaters, movie theaters, high-rise warehouses, and buildings used for commerce,
industry and handicraft, which are usually tall and have large surface areas.
[0002] Systems are known for this purpose that comprise a closed circuit composed of multiple
pipelines which are arranged approximately at the roof or ceiling of the enclosed
space; warm air is circulated inside these pipelines.
[0003] The heating effect is achieved by radiation from the surface of said pipelines towards
the floor by suitable insulating reflecting screens.
[0004] A system of this type is described in Italian patent no. 1,037,880 and GB-A-1 448
073, which includes a burner located directly at the pipeline and a fan for feeding
the gaseous heating medium through the pipeline; the fan is located upstream or downstream
of the burner.
[0005] The burner is of the blast type and is inserted at the pipeline, which has the configuration
of a closed loop.
[0006] This solution has a drawback: the use of air-blast burners in fact produces a preset
pressure in the pipeline, and this pressure requires continuous and accurate maintenance,
which must be performed by extremely qualified individuals, to check for any loss
from said pipeline.
[0007] Further heating systems are disclosed in the prior documents EP-A-0 079 526 and EP-A-0
503 489.
[0008] Furthermore, the use of air-blast gas burners requires the manufacture of devices
which are complicated from a structural point of view and are difficult to optimize;
the large number of moving mechanical parts makes the device prone to breakages, and
thus to considerable maintenance, and entails high overall costs.
[0009] An aim of the present invention is therefore to solve the described technical problems,
eliminating the drawbacks of the described prior art and thus providing a device that
allows to heat enclosed spaces by radiation and has high-level safety characteristics
for its users.
[0010] Within the scope of this aim, an important object is to provide a device that has
very low manufacturing and maintenance costs.
[0011] Another object is to provide a device that is simple to set up, has a limited number
of moving mechanical parts, and allows the use of personnel that is not particularly
trained or qualified.
[0012] Another object is to provide a device for heating enclosed spaces by radiation which
has very low installation costs and is reliable and safe in use.
[0013] With the foregoing and other objects in view, there is provided a device as defined
in the appended claims.
[0014] Further characteristics and advantages of the invention will become apparent from
the detailed description of a particular embodiment, illustrated only by way of non-limitative
example in the accompanying drawings, wherein:
figures 1 and 2 are schematic views of the components of the device;
figure 3 is a sectional view of the fan of the burner;
figure 4 is a sectional view, taken along the plane IV-IV of figure 3;
figure 5 is a schematic view of the use of an air-stream burner.
[0015] With reference to the above figures, the reference numeral 1 generally designates
the heating device for enclosed spaces with any surface extension; said device comprises
at least one pipeline, designated by the reference numeral 2, which forms a closed
circuit that has the desired configuration according to the dimensions of the enclosed
space.
[0016] The device furthermore comprises an atmospheric multiple-flame Venturi-tube or air-stream
burner designated by the reference numeral 3.
[0017] The device is furthermore constituted by a fan, designated by the reference numeral
4, which is interposed at the pipeline 2 in a region that is adjacent to the burner
3 and is preferably contained together with said burner in a suitable containment
element 5 that has an appropriate insulation 6.
[0018] The fan 4 thus draws the burnt gas and sends it into a suitable chamber 7 arranged
laterally to the burner 3; downstream of said burner, the combustion flame gas which
contains a certain amount of air drawn from outside and the burnt gas, mix and allow
to obtain a high-temperature gaseous fluid without the aid of heat exchangers.
[0019] Preferably, a first gate valve 8 for adjusting the air flow-rate is inserted between
the fan 4 and the burner 3.
[0020] The fan 4 furthermore has a second gate valve 9 for adjusting the discharge of fumes
at a suitable discharge duct 10.
[0021] Of course there is a very specific ratio in the mixing of the air that circulates
inside the pipeline 2, of the product of combustion, and of the flame of the atmospheric
gas burner, since the mixed amount of air and gas required for combustion is equal
to the amount of combustion gas that leaves the discharge duct 10.
[0022] In this way, in this device primary air, generally designated by the reference numeral
11, enters the burner 3 due to the negative pressure produced by the jets of pressurized
combustible gas inside one or more Venturi-tube burners and due to the negative pressure
produced by the fan 4 on the feed duct 12 that is associated with said burner.
[0023] As shown in figures 1 and 2, the discharge duct 10 can furthermore be arranged at
the fan 4 or between the fan and the burner 3.
[0024] Furthermore, as shown in figures 3 and 4, advantageously the suction inlet 13 of
the fan 4 is located approximately at the center of the return duct 14.
[0025] As shown in figure 5, an air-stream burner 3 is used wherein the air and burnt gas
mixture is introduced laterally.
[0026] Air is fed upstream of the fan 4 by means of a third gate valve 15.
[0027] The dimensions of the device can be limited in this solution, too, by providing the
fan and the burner in a single unit.
[0028] It has thus been observed that the invention has achieved the intended aim and objects
a device having been provided that allows to heat enclosed spaces by radiation with
extremely high user safety characteristics, since the pipeline is at negative pressure
and thus does not release into the environment any toxic fumes due to accidental leaks
or breakages.
[0029] The possibility of providing in a single unit the fan and the burner, which is of
the Venturi-tube atmospheric type or of the air-stream type, allows to place said
unit in any point outside the enclosed space, due to its limited dimensions with respect
to known systems that have equal capabilities.
[0030] Its simple construction furthermore allows rapid and easy maintenance, which can
be performed even by personnel that is not particularly trained and thus with very
low manufacturing, installation, and management costs.
[0031] As regards the field of application, the described solution can be used to heat a
furnace, for example of the tunnel type.
[0032] The dimensions and the materials that constitute the individual components of the
device may of course be the most pertinent according to the specific requirements.
[0033] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly such reference signs do not have any limiting effect
on the scope of each element identified by way of example by such reference signs.
1. Device for heating enclosed spaces, comprising at least one closed-circuit pipeline
(2) which acts by heat radiation, a burner (3) for providing a flame at the pipeline
(2) for direct heating of a heating medium, and a fan (4) arranged upstream of said
burner (3) at said pipeline for producing a negative pressure therein, said heating
medium being constituted by a mixture of combustion gas and air, characterized in that said burner (3) is a multiple-flame Venturi-tube burner providing a joint flame extending
into a flame tube (16) which laterally surrounds said joint flame so as to provide
a chamber (7) wherein the heating medium is delivered laterally to the flame tube
(16), and is circulated thereabout, whereupon the heating medium mixes, downstream
of said flame tube (16), with flame combustion gas and air drawn from outside due
to the negative pressure created by said fan (4) and by the jets of pressurized combustible
gas inside said multiple-flame Venturi-tube burner.
2. Device according to claim 1, characterized in that said burner (3) is located together
with said fan (4) in a containment element (5).
3. Device according to claims 1 and 2, characterized in that said containment element
(5) has an appropriate insulation.
4. Device according to any of claims 1 to 3, characterized in that said chamber (7) is
a scroll chamber formed between said flame tube (16) and said containment element
(5).
5. Device according to any of claims 1 to 4, characterized in that said pipeline (2)
is arranged outside said containment element (5) and is connected at a first end to
said chamber (7) and at a second end to the suction inlet of said fan (4).
6. Device according to one or more of the preceding claims, characterized in that it
comprises a first gate valve (8) which is interposed between said fan (4) and said
burner (3) and a second gate valve (9) that is connected to a discharge duct (10).
7. Device according to claim 6, characterized in that said discharge duct (10) is located
at said fan (4) or between said burner (3) and said fan (4).
8. Device according to one or more of the preceding claims, characterized in that said
fan (4) has a suction inlet (13) located approximately at the center of said pipeline
(2).
9. Device according to one or more of the preceding claims, characterized in that said
burner (3) has a preheater for heating the combustion air which is suitable to increase
thermal efficiency.
1. Vorrichtung zum Heizen von geschlossenen Räumen, welche mindestens umfaßt eine in
sich geschlossene Rohrleitung (2), welche durch Wärmestrahlung wirkt, einen Brenner
(3) zur Bereitstellung einer Flamme in der Rohrleitung (2) zur direkten Erhitzung
eines Heizmediums, und einen Ventilator (4), welcher stromaufwärts vom Brenner (3)
in der Rohrleitung angeordnet ist, zur Erzeugung eines Unterdruckes darin, wobei das
Heizmedium aus einer Mischung von Verbrennungsgas und Luft gebildet ist, dadurch gekennzeichnet, daß der Brenner (3) ein mehrflammiger Venturirohrbrenner ist, der eine vereinte
Flamme bereitstellt, welche sich in ein Flammrohr (16) erstreckt, das die vereinte
Flamme seitlich umgibt, um eine Kammer (7) bereitzustellen, in welche das Heizmedium
seitlich zum Flammrohr (16) zugeführt wird und um dieses herum zirkuliert, wodurch
das Heizmedium sich stromabwärts vom Flammrohr (16) mischt mit Flammen-Verbrennungsgas
und Luft, welche von außen infolge des vom Ventilator (4) und durch die Strahlen des
unter Druck stehenden Verbrennungsgases innerhalb des mehrflammigen Venturirohrbrenner
erzeugten Unterdrucks angesaugt wird.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß der Brenner (3) zusammen mit dem Ventilator (4) in einem Behälterelement (5)
angeordnet ist.
3. Vorrichtung nach den Ansprüchen 1 und 2, dadurch gekennzeichnet, daß das Behälterelement (5) eine geeignete Isolierung hat.
4. Vorrichtung nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die Kammer (7) eine Spiral-Kammer ist, welche zwischen dem Flammrohr (16) und
dem Schutzbehälter(5) gebildet wird.
5. Vorrichtung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die Rohrleitung (2) außerhalb des Behälterelements (5) angeordnet ist und verbunden
ist an einem ersten Ende mit der Kammer (7) und an einem zweiten Ende mit der Ansaugöffnung
des Ventilators (4).
6. Vorrichtung nach einem oder mehreren der voranstehenden Ansprüche, dadurch gekennzeichnet, daß sie umfaßt einen ersten Absperrschieber (8), welcher zwischen dem Ventilator
(4) und dem Brenner (3) zwischengeschaltet ist und einen zweiten Absperrschieber (9),
welcher mit einem Abzugsrohr (10) verbunden ist.
7. Vorrichtung nach Anspruch 6, dadurch gekennzeichnet, daß das Abzugsrohr (10) am Ventilator (4) oder zwischen dem Brenner (3) und dem
Ventilator (4) angeordnet ist.
8. Vorrichtung nach einem oder mehreren der voranstehenden Ansprüche, dadurch gekennzeichnet, daß der Ventilator (4) eine Ansaugöffnung (13) hat, welche ungefähr in der Mitte
der Rohrleitung (2) angeordnet ist.
9. Vorrichtung nach einem oder mehreren der voranstehenden Ansprüche, dadurch gekennzeichnet, daß der Brenner (3) einen Vorerhitzer zur Erhitzung der Verbrennungsluft aufweist,
der geeignet ist um den thermischen Wirkungsgrad zu erhöhen.
1. Dispositif pour chauffer des espaces fermés, comprenant au moins un circuit tubulaire
fermé (2) qui sert à la répartition de la chaleur, un brûleur (3) pour former une
flamme sur le circuit tubulaire (2) pour le chauffage direct d'un fluide de chauffage,
et un ventilateur (4) disposé en amont dudit brûleur (3) sur ledit circuit tubulaire
pour générer une pression négative dans le circuit tubulaire, ledit fluide de chauffage
étant constitué d'un mélange de gaz de combustion et d'air, caractérisé en ce que
ledit brûleur (3) est un brûleur à tube de Venturi et à flammes multiples produisant
une flamme résultante s'étendant dans un tube de flamme (16) qui entoure latéralement
ladite flamme résultante de façon à constituer une chambre (7) dans laquelle le fluide
de chauffage est délivré latéralement au tube de flamme (16) et y est mis en circulation,
de telle façon que le fluide de chauffage se mélange, à l'aval dudit tube de flamme
(16) avec les gaz de combustion et l'air qui est aspiré de l'extérieur du fait de
la pression négative créée par ledit ventilateur (4) et par les jets de gaz combustibles
pressurisés à l'intérieur dudit brûleur à tube de Venturi et à flammes multiples.
2. Dispositif selon la revendication 1, caractérisé en ce que ledit brûleur (3) est situé
avec ledit ventilateur (4) dans un élément de confinement (5).
3. Dispositif selon les revendications 1 et 2, caractérisé en ce que ledit élément de
confinement (5) comporte une isolation appropriée.
4. Dispositif selon l'une quelconque des revendications 1 à 3, caractérisé en ce que
ladite chambre (7) est une chambre scroll (à tourbillons tangentiels) formée entre
ledit tube de flamme (16) et ledit élément de confinement (5).
5. Dispositif selon l'une quelconque des revendications 1 à 4, caractérisé en ce que
ledit circuit tubulaire (2) est disposé à l'extérieur dudit élément de confinement
(5) et est relié à une première extrémité à ladite chambre (7) et à une deuxième extrémité
à l'entrée d'aspiration dudit ventilateur (4).
6. Dispositif selon l'une ou plusieurs des revendications précédentes, caractérisé en
ce qu'il comporte une première vanne de passage ou vanne (8) qui est interposée entre
ledit ventilateur (4) et ledit brûleur (3) et une deuxième vanne de passage ou vanne
(9) qui est reliée à une tubulure de décharge (10).
7. Dispositif selon la revendication 6, caractérisé en ce que ledit tube de décharge
(10) est situé sur ledit ventilateur (4) ou bien entre ledit brûleur (3) et ledit
ventilateur (4).
8. Dispositif selon l'une ou plusieurs des revendications précédentes, caractérisé en
ce que ledit ventilateur (4) comporte une entrée d'aspiration (13) située approximativement
au centre dudit circuit tubulaire (2).
9. Dispositif selon l'une ou plusieurs des revendications précédentes, caractérisé en
ce que ledit brûleur (3) comporte un organe de préchauffage pour réchauffer l'air
de combustion, de manière à augmenter le rendement thermique.