SECONDARY AIR DEVICE

Description

[0001] The present invention relates to a secondary air device for an exhaust system of one or more fireplaces, comprising a filter attachment.

[0002] Secondary air devices are known in various designs. They serve to limit the chimney draft in a chimney or in the exhaust pipe of an exhaust system. Such secondary air devices typically incorporate draught restrictors for this purpose, which can transition between a closed position and an open position depending on a pressure difference between the interior of the exhaust system and the surroundings. However, within the scope of the present invention, such secondary air devices can also be designed without draught restrictors and thus constitute simple air supply devices.

[0003] Such draught regulators, which may also be known as draught regulators, often consist of a pendulum flap that pivots around a horizontal pivot axis between the specified closed position and the open position. Its response can be adjusted using an adjustable weight. Accordingly, when the aforementioned pressure difference is exceeded, this flap moves to its open position, allowing outside air to flow into the exhaust system as secondary air through an air inlet opening.

[0004] The stronger the negative pressure in the exhaust system created by the chimney draft, the more secondary air is admitted into the exhaust system through the secondary air device to limit the chimney draft. On the other hand, the draft regulator is preloaded to its closed position by the adjusting weight and thus remains in this position when the pressure drops below the predetermined pressure difference. It is understood that in such designs, there is not a single opening position, but rather an angular range with varying degrees of opening can be traversed by the draft regulator, with each of the possible angular positions representing an opening position.

[0005] A common standard variant of such secondary air devices features a short, tubular housing, which, when properly installed, is attached to the exhaust system's exhaust line in the form of a secondary air inlet nozzle. Typically, the secondary air inlet opening and the pendulum flap are arranged in or on the secondary air inlet nozzle so that they are exposed to the outside at the front (air inlet side) of the housing, thus being exposed to the ambient atmosphere.

[0006] Although, during normal operation of a secondary air device of the type under consideration here, the main flow direction runs through the air inlet opening from the outside environment into the exhaust pipe in question, it has been found that soot and dust particles can also escape from the secondary air device through its air inlet opening to the outside, contrary to this main secondary air flow direction, and can be deposited in the vicinity of the secondary air device as accumulations of dirt.

[0007] The escape of such dust and soot particles to the outside, contrary to the main secondary air flow direction, can have various causes, such as turbulent flow components that carry dust and soot particles. It can also happen that pressure fluctuations occur in the area of ​​the secondary air device during commissioning of an exhaust system, which promote the discharge of dust or soot particles to the outside through the air inlet opening.

[0008] Furthermore, such secondary air devices are sometimes operated in such a way that the air inlet flap is opened slightly at high temperatures in the installation room, which can also result in the escape of soot particles or dust particles into the installation room.

[0009] Such dust or soot emissions from the secondary air device can impair the air quality in the room where it is installed, and dust and soot deposits in the room represent unpleasant contamination that should be counteracted. If such soot or dust deposits occur on or in electrical devices, such as heating control units, in the room where the secondary air device is installed, this can impair the functionality of the devices.

[0010] To combat the escape of dust and soot particles from a secondary air device of the type in question, DE 20 2019 102 488 U1, for example, proposed arranging a bag-shaped external filter attachment in the area of ​​the air inlet opening and the pendulum flap, which can prevent solid particles from escaping from the secondary air device. While such an external filter attachment can indeed reliably ensure that no such dust or soot particles enter the outside space, the external attachment of the filter attachment itself has the disadvantage that the filter is exposed to the outside and can therefore, on the one hand, be easily damaged or accidentally torn off, and on the other hand, it presents an unsightly visual appearance, particularly after a certain period of operation.

[0011] DE 20 2016 004840 U1 discloses a secondary air device with a pendulum flap arranged in the air inlet opening.

[0012] Furthermore, reference is made to EP 2 166 287 A2 and US 4 279 629 A, which each disclose filters with a mountable housing and a filter section impermeable to soot and dust particles.

[0013] It is therefore the object of the present invention to provide an improved alternative for the external filter attachment just described, which on the one hand eliminates the disadvantages mentioned and in particular is protected against damage and does not impair the appearance of the secondary air device, but on the other hand just as reliably prevents the escape of dust and soot particles from the secondary air device.

[0014] For this purpose and to achieve the stated object, the invention proposes a secondary air device of an exhaust system of one or more fireplaces, in which a filter attachment comprises a housing and a fixed filter section enclosed therein, wherein the housing is designed such that the filter attachment or filter insert can be mounted between an installation point and a draught limiter of the secondary air device via a mounting system, for example a plug-in system or a clamping band, and the filter section is designed such that it is impermeable to soot and ash particles.

[0015] By placing a filter attachment downstream of the draught restrictor of a secondary air device with respect to the incoming air, it is inaccessible from the outside during normal operation of the secondary air device or fireplace, thus protecting it from damage and the like. Furthermore, the filter attachment is only visible from the outside through its housing, which does not impair the appearance of the secondary air device but is integrated into the existing piping. This improves the prior art solution with regard to the aspects mentioned above, while maintaining the same level of effectiveness.

[0016] Although various materials are conceivable for the filter section of the filter attachment, as long as they do not present excessive resistance to the airflow through the secondary air device and can reliably retain soot and dust particles, it can, in particular, comprise or be formed from a suitable foam ceramic, a ceramic body, or another filter medium. The shape of the filter insert is also essentially freely selectable, and filter inserts can be round, square, or formed with a cut-off section that functions as a bypass.

[0017] In order to facilitate the cleaning of the filter section after a predetermined period of time, it may alternatively or additionally be designed to be cleaned under running water, for example by means of a fine brush or the like.

[0018] Although excessively high temperatures should not occur at the installation position of the filter attachment during operation of the fireplace, the filter section of the filter heel can nevertheless be designed in such a way that it is non-flammable and resistant to exhaust gases in order to exclude any risk of fire at this point.

[0019] Furthermore, for simplified installation and easy replacement, the filter attachment can be designed such that its housing includes a clamping band, allowing installation via the aforementioned plug-in system. This allows the filter attachment to be replaced in just a few simple steps. In this context, embodiments that include a clamping band with a foam ceramic, a ceramic body, or another filter medium inserted therein are also conceivable. Square variants, for example, are also conceivable, which can then be installed via guide rails if necessary.

[0020] In principle, filter attachments can be combined with any type and design of draught regulator. Therefore, a corresponding filter attachment can be configured for use with draught regulators with a diameter between 80 and 250 mm and can itself have a diameter between 80 and 250 mm.

[0021] Furthermore, according to the invention, the filter section can be formed such that a free cross-section remains within the secondary air device. This creates a bypass through which the exhaust gases can flow freely. For this purpose, the filter section can be cut off in an edge region thereof such that the aforementioned free cross-section remains within the secondary air device.

[0022] As mentioned above, the present invention relates to a secondary air device for an exhaust system of one or more fireplaces, comprising a pipeline with an installation location for a draught restrictor, such a draught restrictor, wherein the draught restrictor has an air inlet opening for admitting secondary air into the exhaust system and a pendulum flap for opening and closing the air inlet opening, and the draught restrictor is mountable by means of a plug-in system, and a filter attachment of the type just described, wherein the filter attachment is mounted between the installation location and the draught restrictor. As already mentioned above, the present invention can also be used in configurations in which a draught restrictor is dispensed with, thus forming a simple supply air device.

[0023] This shows that the installation of the filter attachment described above is possible both with existing draught regulators using the existing plug-in system and with new systems. This combination of a filter attachment and a precisely adjustable draught regulator combines the advantages of a draught regulator with a clean installation room, namely compensation for weather-related negative pressure fluctuations, a reduction in the dew point and thus later condensate formation, and smoother combustion in the fireplace, which in turn can lead to clean combustion chamber viewing windows and lower emissions, as well as lower fuel consumption and therefore more economical operation of the fireplace. Furthermore, for the reasons mentioned, more environmentally friendly operation of the fireplace is enabled, whereby the simple and cost-effective design of the filter attachment and thethe secondary air device of the present invention only very short amortization periods can be expected, while nevertheless the soot and dust discharge into the installation room is reliably minimized.

[0024] As already mentioned above, the draught limiter of the secondary air device according to the invention can comprise a mounted pendulum flap that can be pivoted between a closed position and an open position, wherein the response behavior of this pendulum flap can be adjusted, in particular by means of an adjusting weight.

[0025] Further features and advantages of the present invention will become more apparent from the following description of an embodiment thereof, when considered together with the accompanying figures. These show in detail: Figures 1A and 1B show an embodiment of a secondary air device according to the invention with a filter attachment in a closed position; Figures 2A and 2B show the secondary air device from the Figures 1A and 1B in an open position; Figures 3A to 3D show an alternative variant of a secondary air device according to the invention with a filter attachment.

[0026] In the Figures 1A and 1B a secondary air device for an exhaust system of one or more fireplaces is shown in a front view and a cross-sectional view and is generally designated by the reference numeral 10.

[0027] In this case, a secondary air inlet nozzle 14 is arranged laterally on a pipe 12 to be integrated into a respective exhaust line, which acts as an installation point for the draught restrictor 16 described below. On the front side, this draught restrictor 16 has an air inlet opening 18, which is arranged in the Figures 1A and 1Bshown operating position is closed by a pendulum flap 20 which is mounted so as to be able to swing around a horizontally arranged pendulum axis 22 and whose response behavior can be adjusted by means of an adjusting weight 24 in that this can be linearly displaced with regard to its position with respect to the pendulum axis 22 in order to produce correspondingly adapted lever ratios.

[0028] Here, the term response behavior refers to the pressure difference between an interior of the exhaust line 12 and the exterior of the secondary air device 10, from which the pendulum flap 20 moves from its Figures 1A and 1B shown closed position into the position shown in the Figures 2A and 2B shown opening position to allow the entry of an air flow, which is indicated in Figure 2B by an arrow P. In particular, the opening angle of the pendulum flap 20 depends on the acting pressure difference and in addition to the fully closed position from the Figures 1A and 1Band the essentially fully open position from the Figures 2A and 2B Any intermediate positions can also be taken by the pendulum flap 20, as shown in Figure 2B indicated by an arcuate dashed line.

[0029] Furthermore, it should be noted that the individual parts of the secondary air device 10 are connected to one another via a plug-in system 26, which enables simple assembly and replacement of individual components, in particular the filter attachment or filter insert 30 described below.

[0030] According to the invention, in the Figures 1A to 2BThe filter attachment or filter insert 30 is integrated into the secondary air device 10 shown. The filter attachment or filter insert comprises a housing 32 with a clamping band 34 and a filter section 36 made of a suitable foam ceramic, a ceramic body, or another filter medium. This filter section 36 allows ambient air to enter the pipe section 12 through the open pendulum flap 20, but simultaneously prevents soot or dust particles from escaping, for example due to the effect of turbulent air currents, while the draft regulator 16 is in its open position.

[0031] The provision of the clamping band 34 enables simplified installation of the filter attachment 30 in the secondary air device 10, which is mounted by means of the aforementioned plug-in system 26. Consequently, simple retrofitting of such a filter attachment 30 is just as possible as the integration of a filter attachment 30 into a secondary air device 10 being installed for the first time.

[0032] In the Figures 3A to 3D Finally, an alternative variant of a secondary air device according to the invention with a filter attachment is shown and generally designated by the reference numeral 100. Here, components of the secondary air device 100 which are similar or identical to corresponding components of the embodiment from the Figures 1A to 2Bare designated by the same reference numerals, each increased by 100. Furthermore, for the sake of brevity, a duplication of descriptions of the components present equally in both versions is omitted.

[0033] The main difference between variant 100 from the Figures 3A to 3DOne advantage is that the secondary air device 100 is not provided with a draught limiter and is thus designed as a simple supply air device. Furthermore, in variant 100, the filter section 136 is separate from the clamping band 134 and is provided as an insertable, suitable foam ceramic, ceramic body, or other filter medium. It is only clamped into its intended position in the secondary air device 100 by inserting and tightening the clamping band, thereby forming a corresponding housing 132. In further alternative variants, the installation of a round or square filter insert could also be carried out, for example, using guide rails.

[0034] Another possible variant is, as in 3D figureshown, is to provide a filter section 136' which has a shape that does not fill the entire cross-section of the secondary air device 100, but leaves a bypass section with a free cross-section. For this purpose, the corresponding foam ceramic or the ceramic body or another filter medium is 3D figure The area shown above is cut off in such a way that the mentioned free cross-section remains within the secondary air device 100.

Claims

1. Secondary air device (10) for an exhaust system of one or more fireplaces, comprising: - a pipe (12) with an installation point (14) for a draught limiter (16), - a draught limiter (16), wherein the draught limiter (16) has an air inlet opening (18) for admitting secondary air into the exhaust system and a pendulum flap (20) for opening and closing the air inlet opening (18), and the draught limiter (16) is mountable by means of a push-fit system (26), and characterised by: - a filter attachment (30) which is mounted between the installation point (14) and the draught limiter (16), the filter attachment (30) comprising a housing (32) and a fixed filter section (36) enclosed therein, the housing (32) being configured such that the filter attachment (30) is mounted between the installation point (14) and the draught limiter (16) via a mounting system, for example a push-fit system (26) or a clamping band, and the filter section (36) being configured such that it is impermeable to soot and dust particles.

2. Secondary air device (10) according to claim 1, characterised in that the filter section (36) comprises or is formed from ceramic foam, a ceramic body or another filter medium.

3. Secondary air device (10) according to claim 1 or 2, characterised in that the filter section (36) is adapted to be cleaned under running water.

4. Secondary air device (10) according to any of the preceding claims, characterised in that the filter section (36) is incombustible and resistant to exhaust gas.

5. Secondary air device (10) according to any of the preceding claims, characterised in that the housing (32) comprises a clamping band (34) that enables mounting via the push-fit system (26).

6. Secondary air device (10) according to any of the preceding claims, characterised in that the filter attachment (30) is adapted to be used with draught limiters (16) having a diameter between 80 and 250 mm.

7. Secondary air device (10) according to any of the preceding claims, characterised in that the filter section (136') is formed in such a way that a free cross-section remains within the secondary air device (10).

8. Secondary air device (10) according to any of the preceding claims, wherein the pendulum flap (20) is pivotable between a closed position and an open position.

9. Secondary air device (10) according to claim 8, wherein the response behaviour of the pendulum flap (20) can be adjusted by means of an adjustment weight (24).