DK2290298T3 - Hood with a shunt to divert an airflow - Google Patents

Description

The invention relates to a fume extraction hood with a diverter device for diverting a stream of air according to the preamble to Claim 1.

It is well known that fume extraction hoods of this type are used in order to operate the latter alternately, as desired or needed, either in exhaust mode or in circulation mode, in the first case the air filtered in the fume extraction hood flowing out into the open through an exhaust duct, whereas in the other case it flows back into the installation area as circulated air. Switching from one mode into the other takes place here by swivelling the divert flap into the respective switching position. A fume extraction hood of this type is disclosed by EP-A-1 055 883. The diverter device is fully integrated into the fume extraction hood here. It is therefore impossible to make the device variable so that it can be adapted to predetermined conditions of use and existing duct connections without a great deal of effort. Moreover, it is a disadvantage that maintenance or repair of the diverter device has to take place directly on the fume extraction hood, and this generally requires longer interruptions in operation.

In publication DE-A-10 2006 024 658 a device for fume extraction hoods for alternating between circulation and exhaust mode is disclosed wherein a pipelike housing is connected in horizontal alignment to a nozzle or, lying opposite, to a pipe for the exhaust air. In addition, an opening leading away transversely for circulation mode is assigned to this pipe-like housing. A swivelable divert flap in the house enables one to alternate between circulation and exhaust mode. A disadvantage with this device is this pipe-like housing which is only provided with one opening for the circulation mode.

In publication DE-A-30 40 051 a control apparatus for exhaust or circulating air devices, in particular for fume extraction hoods, is described, wherein an inlet and an outlet opening, and in addition a part with an outlet opening for the circulation path are provided in the form of a three-way valve. For resetting of the three-way valve a swivelable flap is mounted rotatably therein, by means of which the air to be discharged is conveyed outwards or back into the room or, with a mixed mode, both outwards and back into the room. This control apparatus is integrated directly into the housing of the fume extraction hood here, and this is constructionally complex.

In an apparatus for regulating the mixture of a stream of air according to published examined application DE-1 227 743, two flaps mounted such that they can swivel are arranged in relation to one another by means of a gearing mechanism within a housing such that they swivel symmetrically in relation to the axis of the passage so that the passage or the side openings in the housing are either opened or closed.

The object underlying the invention is to avoid these disadvantages and to devise a fume extraction hood of the type specified at the start which can be used with different operating conditions and duct connections.

According to the invention, this object is achieved by a fume extraction hood that has the features of Claim 1.

Preferred embodiments are defined in the dependent claims.

In this way, the diverter device forms a separate unit the structure of which can be determined from case to case according to the respective features of the system. The unit can be dismantled at any time in order to change or repair the module.

In order to facilitate installation of the diverter device, the invention makes provision such that its connection on the outlet side preferably has standardised sizes and configurations so that it can be connected without any problem to the duct connections which are generally also standardised.

The connection on the outlet side is advantageously disposed in a replaceable cover of the housing. It is thus possible to provide the diverter device with the appropriate connection without having to replace the whole module for this purpose.

For the purpose of the quietest possible operation, the bottom wall of the housing is provided with insulation of a sound and vibration absorbing material which reduces the acoustic and mechanical load caused by the suction fan of the fume extraction hood.

In a first embodiment the diverter device is equipped with an outlet at the front side for the exhaust mode and two lateral outlets for the circulation mode, the exhaust air flowing out in the axial direction of the fume extraction hood, whereas the circulating air flows back into the space where the system is installed on both sides transversely to its axial direction. This configuration is generally advantageous in view of the normally available spatial conditions.

The additional lateral outlet is preferably positioned directly opposite the other lateral outlet here, and together with the latter distributes the circulating air more evenly. In this case two divert flaps can preferably be switched synchronously.

In the above embodiment it is also possible to switch the divert flaps into intermediate positions in which the system can be operated in combined exhaust and circulation mode.

For the purpose of the quietest possible operation insulation made of sound and vibration absorbing material is also provided in the region of the lateral outlets.

Optionally, the divert flaps can be swivelled in opposite directions by means of toothed gear segments engaging with one another and on which the flaps are fastened laterally to them. This type of drive is very simple from a constructional and a control point of view, and moreover offers the advantage that it ensures that the synchronic switching of the flaps takes place automatically.

The toothed gear segments are advantageously produced from plate-type material and are disposed in a plane close to an inner wall of the housing. In this way a large free passage channel is produced in the installation space through which the exhaust air flows without any hindrance.

Advantageously, the toothed gear segments can be actuated with a drive that is preferably in the form of an electric motor which is attached to an outer wall of the housing and drives the axis of rotation of the one toothed gear segment in order to swivel the divert flaps into the desired switching position. This type of drive is space-saving, light, has fine control and moreover is easily accessible for any necessary handholds.

In order to increase the functional reliability of the diverter device it is advantageous to provide one of the toothed gear segments with a part-circle-shaped groove that interacts with a stop bolt that delimits the angle of rotation of the toothed gear segments.

In the following the invention will be described in more detail by means of an exemplary embodiment with reference to the drawings. These show:

Fig. 1 the fume extraction hood according to the invention with a diverter device, shown perspectively, and Fig. 2 the diverter device from Fig. 1, shown in section and enlarged.

The fume extraction hood 1 illustrated in Fig. 1 has a prismatic shaft 2 in which a non-visible exhaust fan and a filter device, that is not visible either, generally consisting of an odour filter and a grease filter, are fitted. An inlet funnel 3 that conveys the exhaust air into the shaft 2 is disposed on the shaft 2 on the inlet side.

There is disposed at the end of the shaft 2 on the outlet side a diverter device 4 with which the exhaust air flowing through the shaft 2 can either be diverted into an exhaust duct 5 or as circulating air into the installation space 6 of the system.

The diverter device 4 has a housing 7 that, as can be seen from Fig. 2, is provided with an inlet 8 on the bottom side, an outlet 9 on the front side for the exhaust mode and two lateral outlets 10a, 10b lying opposite one another for the circulation mode. Also disposed in the housing 7 are two divert flaps 11a, 11b that can be swivelled between the outlet 9 and the outlets 10a, 10b and which can be driven in opposite directions by toothed gear segments 12a, 12b engaging with one another. The latter are also produced as flat toothed wheel discs made of sheet metal which can be rotated about their axes of rotation 13a, 13b in a plane close to a side wall 14 of the housing. The inlet 8 on the bottom side can be connected directly to the extraction hood, as shown, or to a duct disposed in between.

The divert flaps 11a, 11 b are fastened to the toothed gear segments 12a, 12b transversely to their common plane. In the operating position shown in Fig. 2, they are swivelled out with respect to slightly inclined bearing surfaces 15a, 15b and close the lateral outlets 10a, 10b, whereas the outlet 9 on the front side as well as the opposite inlet 8 in the bottom wall 16 of the housing 7 are open. In this switching position the exhaust air sucked into the shaft 2 is conveyed through the passage channel delimited by the flaps 11a, 11b and the side walls of the housing, and can flow out into the open through the adjoining exhaust duct 5. Since the toothed gear segments are thin and positioned close against the side wall 14 of the housing, the exhaust air can flow through a relatively large free passage cross-section without any hindrance.

In the switching position shown with dots and dashes, the flaps 11a, 11b shut off the passage channel and at the same time open the two lateral outlets 10a, 10b so that the exhaust air flows back through the latter as circulating air into the installation space 6 of the system. In this switching position the flaps 11a, 11b lean against additional bearing surfaces 17a, 17b. The latter are disposed almost perpendicularly to the bearing surfaces 15a, 15b. In order to increase the functional reliability of the diverter device, one toothed gear segment 12b is provided with a part-circle-shaped groove 18 that interacts with a stop bolt 19 delimiting the angle of rotation of the toothed gear segments 12a, 12b.

The toothed gear segments 12a, 12b can be actuated with an electric motor 20 by means of which the axis of rotation 13a of the toothed gear segment 12a can be driven. The electric motor 20 is attached to an outer wall 21 of the housing 7 such as to be easily accessible. It only requires a simple control and a small amount of space, is easy to maintain and can be replaced if so required. Instead of the electric motor, other correspondingly small and functionally reliable drives can also be used.

The housing 7 with the diverter device 4 forms a separate unit that can be connected on the inlet side to the shaft 2 of the fume extraction hood 1 and on the outlet side to the exhaust duct 5 shown with dots and dashes. The connection 22 on the inlet side is disposed in the bottom wall 16 of the housing. The standardized connection fitting 23 is located in the cover 24 that is fastened securely to the housing 7. Both connections have standardized configurations and sizes that correspond to those of the shaft 2 and of the exhaust duct 5. This facilitates both the assembly of the fume extraction hood and its connection to the system’s exhaust duct.

The structure according to the invention of the diverter device 4 as a modular unit enables one to adapt the latter to the respective conditions of use by choosing the appropriate module. Moreover, it is thus possible to use standardized fume extraction hoods and standardized exhaust ducts, and this is associated with considerable financial advantages. Moreover, repair of the diverter device is also very much facilitated because it can take place outside of the system, for example by changing the module.

In order to provide the module with the appropriate connection on the outlet side, it is only necessary to provide the housing 7 with the correspondingly formed cover 24.

The bottom wall 16 has an insulation 25 of a sound and vibration absorbing material which reduces the noise and vibration disturbance caused by the suction fan. For this purpose material insulation 26, 26b is also provided in the region of the lateral outlets 10a, 10b.

As an alternative and in contrast to Fig. 1, according to Fig. 2 a duct 5 similar to that in the outlet is provided in the inlet, and this duct can then be connected to the extraction hood or the like.

The diverter device described has two lateral outlets 10a, 10b in order to convey the circulating air more evenly into the installation space 6 than would be the case with just one lateral outlet opening.

Claims (5)

A hood (1) with a bypass device (4) for diverting an air flow, wherein the bypass device (4) is provided with outputs (9, 10a, 10b) and at least one bypass valve (11a, 11b) which can be rotated between these outputs , where on the front side there is provided an outlet (9) for connecting to an exhaust air line (5) for exhaust mode and in the side an outlet (10a) for air circulation mode, in which the by-pass device (4) is provided with a housing (7) as a module in which the housing (7) on the input side can be connected to the hood (1) and is provided with the output (9) on the front side for blow-out mode, characterized in that the housing (7) is further provided with an additional outlet (10b) in the side for air circulation mode, in which, in each case, a bypass flap (11a, 11b) is assigned to the side outputs (10a, 10b), in which, in a coupling position, these bypass valves (11a, 11b) block the output (9) at the same time opens the two outputs (10a, 10b) i the side, and where these bypass valves (11a, 11b) in a different coupling position close the outputs (10a, 10b) in the side and open the outlet (9) on the front side. Hood according to claim 1, characterized in that a connecting spout (23) is arranged in a cover (24) of the housing (7). Hood according to claim 2, characterized in that a connection on the output side which forms the connection socket (23) has standardized sizes and devices. Hood according to claim 1, characterized in that the bypass valves (11a and 11b) can each be coupled to an intermediate position, where combined exhaust and air circulation modes are possible. Hood according to claim 1, characterized in that a connection (22) on the entrance side is arranged in a bottom wall (16) of the housing (7) provided with an insulation (25) of noise and vibration damping material.