EP0036364B1 - Method of connecting a gas fired heater of the sealed and forced draught type to a conventional chimney - Google Patents

Description

The present invention relates to a method for connecting to a normal or conventional flue, a gas boiler of the sealed type with forced draft and, especially, a sealed boiler using a body of the condensing heat exchanger associated with a burner to air and gas premix using a fan on the combustion air.

We know that one of the main criticisms that can be made against the development of the installation of gas boilers of the sealed type with forced draft through a microventacle, is the appearance of plumes of steam leaving more or less perpendicularly to the facades of buildings or houses by the orifice for evacuating the products of combustion from the micro-suction cup.

These plumes of vapor, although appearing only under certain conditions of temperature and hygrometry of the atmosphere, are criticized by the architects, who, on the one hand fear that this vapor will cause condensation on the facades and, starting from there, risks of more or less serious degradation, detrimental to their aesthetics and, on the other hand, they also fear that these jets of vapor will be criticized by the users themselves or their immediate neighbors who could see a factor of pollution.

We also know that with the development of gas boilers of the sealed type using a condensing heating body, a highly desirable development due to the significant energy savings that can be achieved with the generalization of this type of boiler. , the appearance of these steam plumes will occur much more frequently due to the fact that on these very high-efficiency condensing boilers, the combustion products very often exit at a temperature close to or lower than their dew point temperature.

It would be very unfortunate if the development of these very high efficiency condensing boilers was hindered or hampered by the drawbacks mentioned above and which cannot be underestimated.

The present invention provides a method which makes it possible to use a conventional chimney or flue for both supplying the sealed boiler with combustion air and evacuating the combustion products while also ensuring the collection and evacuation of the water which may come from the condensation of residual water vapor contained in the products of combustion.

It is known to use two coaxial tubes for the evacuation of combustion products and the supply of fresh air to the appliance as described in patents US-A 2,619,022, US-A 2,711,683 and GB- A 1 412497, but these are rigid tubes designed for structural work at the time of construction, while the invention shows a system for adapting to a conventional chimney originally intended for the sole evacuation of exhaust gases. combustion.

According to the invention, the normal or conventional chimney flue existing in the construction is connected to the air intake chamber of the boiler and a flexible pipe of smaller diameter is introduced inside this flue which itself connects to the burnt gas outlet of the appliance, the other end of which opens out from the chimney outside the building.

According to an additional characteristic of the invention, the connection of the central pipe to the orifice for evacuating the burnt gases from the device is ensured in such a way that the condensation water flowing in said pipe is collected in the device. with the condensed water coming from its exchanger.

• fig.1: une vue schématique générale d'un mode de raccordement d'une chaudière à un conduit de fumée,
• fig. 2: une vue à plus grande échelle de la sortie de cheminée de la fig. 1,
• fig. 3: une vue à plus grande échelle du raccordement appareiltubulure dans le cercle de la fig. 1.

The following description of an embodiment taken by way of nonlimiting example will highlight the advantages of the invention as well as its other characteristics. Reference is made to the appended drawings which represent:

• Fig. 1: a general schematic view of a method of connecting a boiler to a smoke duct,
• fig. 2: a view on a larger scale of the chimney outlet of FIG. 1,
• fig. 3: a view on a larger scale of the connection of the tubing device in the circle of FIG. 1.

A condensing boiler designated as a whole by the reference 1 is placed in a room having a chimney flue 3 opening to the outside of the construction or of the building above the roof 4, by a chimney proper designated in as a whole by reference 2.

The condensing type boiler essentially comprises a blast air burner 10 placed inside a circular exchanger 11, a flue gas collecting box 12 with its discharge orifice 13, a pipe 14 for discharging the water of condensation taking up at the base of said collecting box and a duct 15 for admitting the air-gas mixture to the burner by means of the fan 18.

This duct 15 is connected with an air intake chamber 16 as well as with a small gas inlet duct 17, so that the mixing takes place before the arrival at the burner.

The air intake chamber 16 is connected by a sleeve 19 to the chimney pipe 3 existing in the construction. Inside this duct 3 is introduced a flexible tube 5, - for example a flexible stainless steel pipe -, of smaller diameter, the lower end of which is connected to the orifice 13 for evacuating the burnt gases from the 'device, and whose opposite end opens from the chimney 2 above the roof. This tubing 5 serves to evacuate the burnt gases outside while the fresh air necessary for the combustion is sucked in from the outside through the pipe 3 itself.

At the bottom, as shown in fig. 3, the tubing 5 is connected to the orifice 13 for evacuating the burnt gases by means of a collar 6 allowing the condensed water flowing in the tubing to enter the manifold housing 12 and to be evacuated - like, moreover, the condensation water recovered at the exchanger 11 - through the evacuation pipe 14.

At the top, as seen more clearly in fig. 2, the pipe 5 opens at the top of the chimney 2. A device playing the role of a balanced microventacle is sealed on the upper orifice of this chimney for all winds blowing from any direction.

This device is in the form of a vertical pottery with two lanterns 20 and 23 whose upper and lower orifices are protected from rain to an incidence of at least 45 ° by caps 24 and 25. The upper lantern 23 is separated from the lower lantern 20 by a horizontal circular partition pierced in its center with an orifice 22 to which the upper end of the flexible tube 5 is tightly connected. The lower lantern 20 is provided with lateral lights 21 of fresh air to the chimney 3, while the upper lantern 23 has side lights 26 for the evacuation of combustion gases. In the chimney flue 3, the arrangement of the pipe 5 is arbitrary, that is to say that it can have inflections, follow the deviation of the chimney, or even apply against an edge of the flue, without in no way obstruct the passage of fresh air since the diameter of the tubing is significantly less than that of the duct. Therefore no particular precaution is to be taken at the time of the introduction of the tubing into the duct which therefore allows the use of more or less rigid tubing depending on the configuration of the chimney, without worrying about the the way it is positioned inside. In addition, this method still has the advantage of even being able to use a chimney flue in poor condition since its role will only be to serve as an air supply duct and as any leaks it may have have no untoward impact.

Finally, thanks to the collar 6, all the condensation water from the tubing is recovered in the device, and joins the water coming from the exchanger itself.

Claims (5)

1. A process of coupling, to the exterior, a gas heater (1) of forced draught room sealed type comprising a fan (18) for extraction of the burnt gases and/or the admission of fresh air and using a tube for evacuation of the products of combustion coaxial with a fresh air inlet tube to the apparatus, characterized by the fact that the tube for evacuation of the products of combustion is a flexible tubing (5) which couples to the orifice (13) for evacuation of burnt gases from the heater and which is introduced to the interior of the normal or conventional flue conduit (3) existing in the construction and whose base connects to the chamber (16) for admission of air to the heater; and in that said flexible tubing (5) is not applied against the walls of the flue (3) thus leaving a space sufficient for the passage of fresh air necessary for the heater.

2. A process according to claim 1, characterized by the fact that the flexible tubing (5) of small diameter occupies any position in the flue conduit (3) of greater diameter and only presents with said conduit given points of contact at the eventual levels of points of inflexion.

3. A process according to claim 1, characterized by the fact that a sleeve (19) of diameter greater than the tubing (5) and surrounding this tubing ensures coupling of the base of the flue conduit (3) to the chamber (16) for inlet of air to the heater.

4. A process according to claim 1, characterized by the fact that the lower end of the tubing (5) couples to the orifice (13) for evacuation of burnt gases from the heater by means of a collar (6) which receives water of condensation.

5. A process according to claim 4, characterized by the fact that the collar (6) directs the water of condensation towards the interior of the collector box (12) of the heater.

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