System for preventing odor nuisances

Abstract

System (1) for preventing odor nuisances, in particular for a kitchen exhaust system, comprising at least one airflow inlet (9) for the entry of an airflow (10) and at least one airflow outlet (12) for the exit of the airflow (10), wherein the system (1) comprises at least one airflow blower system (11) for drawing in and accelerating the airflow (10), wherein the airflow outlet (12) is arranged and oriented relative to an exhaust airflow outlet (8) such that the airflow (10) accelerates an exhaust airflow (4) exiting the exhaust airflow outlet (8) downstream of the exhaust airflow outlet (8), wherein the airflow outlet (12) comprises an annular gap (18) and / or nozzle ring (20) at least partially enclosing the exhaust airflow outlet (8), characterized in thatthat at least one exhaust air blower system (6) is provided for drawing in and accelerating the exhaust air stream (4) and that at least one control unit (14) controls the air stream blower system (11) and / or the exhaust air blower system (6) such that the volume flow of the air stream (10) at the air stream outlet (12) is higher than the volume flow of the exhaust air stream (4) at the exhaust air stream outlet (8).

Description

[0001] The present invention relates to a system for preventing odor nuisances, in particular for a kitchen exhaust system, with at least one airflow inlet for the entry of an airflow and at least one airflow outlet for the exit of the airflow according to the preamble of claim 1.

[0002] A common problem in urban areas is exhaust air emissions from indoor spaces, particularly from private and commercial kitchens. This exhaust air contains grease, dirt, and odors that can contaminate neighboring buildings through grease deposits and are perceived and disturbed by people in the vicinity.

[0003] To reduce the disadvantages of exhaust air emissions, solutions are known which mix fresh air into the exhaust air before it is released into the environment, thereby diluting the exhaust air and reducing odor nuisance.

[0004] DE 27 59 072 A1 discloses a device for preventing odor nuisances in stables. For this purpose, fresh air is supplied to the exhaust air of the stable via fresh air ducts that are directed upwards in a nozzle-like manner from bottom to top into a deflector hood at the end of a ventilation shaft.

[0005] German patent DE 26 07 712 A1 describes an exhaust air mixing hood for a fireplace, which has a circumferential opening for drawing in outside air. The outside air is drawn in by a suction effect and mixes with the chimney exhaust air, so that its pollutant concentration can be reduced when it leaves the hood.

[0006] DD 2 19 053 A3 discloses a device for mixing exhaust air with ambient air. The device comprises a jacket section which is arranged in the direction of flow above the end of an exhaust pipe, so that ambient air is drawn in, which is intended to contribute to cooling the exhaust pipe.

[0007] From DE 42 11 755 A1 and US 4 654 508 A, ovens with an air extraction device are known which allows fumes or exhaust air to enter a flow shaft via an inlet point, whereby the fumes or exhaust air are drawn into the shaft by a suction effect.

[0008] DE 20 2007 012 095 U1 describes a constant air system for an extractor hood, which includes an exhaust air device and a supply air device designed in such a way that the amount of exhausted air is provided by at least the same amount of supplied air.

[0009] CN 2 06 973 657 U describes an exhaust system in which compressed air is blown through a nozzle into an annular channel by means of a compressor, so that smoke or (oil) vapors are extracted. A small volume of compressed air is used to move a multiple of the exhaust air.

[0010] From WO 89 / 11 926 A1, a system for mechanical local venting is known in which an airflow is used that has a substantially uniform velocity at a constant distance from the injection point and that does not mix with a central, upward-directed exhaust air column. For this purpose, nozzles are arranged around the exhaust air duct, with the inlet and outlet air occurring in the same plane and the inlet direction being tangential to the airflow.

[0011] In the aforementioned publications, the dilution of the exhaust air is achieved by drawing fresh air along with the accelerated exhaust air, followed by a mixing of the two. However, the mere dilution of the exhaust air is generally insufficient to overcome the disadvantages of continuous exhaust air emissions described above.

[0012] Therefore, further efforts were undertaken to treat the exhaust air in such a way that the disruptive grease, dirt, and odor components are removed before being released into the environment. For example, DE 10 2012 012 689 A1 describes a method for operating a kitchen exhaust system in which the kitchen exhaust air is treated with a cleaning agent before it reaches the exhaust duct.

[0013] However, such methods are very complex and involve high operating costs, as the cleaning agent is a consumable. Furthermore, the exhaust system itself is complex and requires intensive maintenance, since components within the exhaust duct must be cleaned regularly. It is therefore an object of the present invention to provide a simple and cost-effective system for preventing odor nuisances, which reduces exhaust air emissions from interior spaces, particularly kitchens and / or cooking areas, for neighboring buildings and people in the vicinity, at least to such an extent that these emissions are no longer perceived as bothersome or at least no longer perceived as such.

[0014] This problem is solved according to the invention by a system having the features of claim 1.

[0015] The system according to the invention, particularly for a kitchen exhaust system, comprises at least one airflow inlet for the entry of an airflow and one airflow outlet for the exit of the airflow, and at least one airflow fan system for drawing in and accelerating the airflow. A key aspect of the invention is that the exhaust air outlet and the airflow outlet are arranged and aligned relative to each other such that the airflow accelerates the exhaust airflow downstream of the exhaust air outlet. In simplified terms, the airflow fan system accelerates the airflow, and this accelerated airflow then accelerates the exhaust airflow after it has been released into the environment, essentially operating under negative pressure.

[0016] The invention is based on the fundamental idea that the exhaust air is carried away from the emission source, in particular the exhaust air outlet, by the airflow, thus preventing disturbance of the environment surrounding the emission source. This prevents odor nuisance and environmental pollution caused by dirt, odors, and pollutants carried along in the exhaust air.

[0017] Visually, the airflow performs a function typically carried out by chimneys: providing lift for the exhaust air and ensuring that the exhaust air is only dispersed at a distance, thus diluting it to a level where it is no longer perceived as bothersome. A further advantage is that the invention does not require maintenance-intensive and costly exhaust air purification methods or devices, as no system components are exposed to the exhaust airflow. Therefore, retrofitting existing exhaust air systems is cost-effective, and no parts that could be contaminated by the exhaust airflow are used or required, thus eliminating the need for increased maintenance and cleaning efforts.Finally, the invention allows for the removal of exhaust air from the emission source in a way that is largely invisible to the eye, which can be an important criterion, especially for prestigious buildings such as hotels.

[0018] In the simplest case, the exhaust air inlet and outlet are connected only by an exhaust air duct, thus preventing contaminating particles from entering the exhaust air stream. However, it is also possible to incorporate additional exhaust air purification between the inlet and outlet.

[0019] The exhaust air inlet is preferably connected to a vapor extraction system or a range hood and, in the simplest case, directly connected to the vapor extraction system.

[0020] The exhaust air outlet and / or the airflow outlet preferably opens directly into the environment, i.e., a room area located outside the system and the room area to be ventilated, in particular an area outside the home.

[0021] The airflow inlet and outlet can also be connected by a simple airflow duct. Typically, the airflow fan system is also located within the airflow connection between the inlet and outlet and can therefore be positioned within the duct. In the simplest and most cost-effective case, the airflow consists of normal ambient air. This ambient air can enter the building through the airflow inlet from either outside or inside the building. Preferably, the airflow contains so few fragrances that the odor thresholds of the respective fragrances are not exceeded.

[0022] The airflow blower system draws in air, for example from the surroundings, and accelerates it. In other words, the airflow blower system increases the volume flow of the airflow in its direction of flow.

[0023] Within the scope of this invention, volume flow refers to the average flow rate of the respective fluid.

[0024] The arrangement and orientation of the exhaust air outlet and the airflow outlet are crucial for accelerating the exhaust airflow. The arrangement of the respective outlets must be such that at least a portion of the exhaust airflow and the airflow overlap, thereby increasing the volume flow of the exhaust airflow. Therefore, it may often be necessary to position the exhaust air outlet and the airflow outlet directly adjacent to each other. In particular, the distance between the exhaust air outlet and the airflow outlet must not be so great as to prevent the exhaust airflow from being accelerated by the airflow.

[0025] The aforementioned superposition of exhaust airflow and airflow can also be illustrated using the Venturi principle. The acceleration of the exhaust airflow and the resulting volume flow create a negative pressure, which in turn accelerates the exhaust airflow.

[0026] In addition to accelerating the exhaust airflow, it is also advantageous that the acceleration of the exhaust airflow by the airflow causes a mixing of the streams, which dilutes the exhaust airflow and thus further reduces odor nuisance.

[0027] A further advantage of the system according to the invention is that it can be retrofitted to existing kitchen exhaust systems, since no components need to be installed within the exhaust air stream. Accordingly, no structural modifications to the existing kitchen exhaust system are necessary. Furthermore, it is sufficient to install the system according to the invention at an exhaust air outlet that is regularly accessible from the outside, which minimizes the required structural work. Therefore, no structural modifications are necessary inside the building, so that, for example, kitchen operations are not disrupted.

[0028] The orientation of the exhaust air outlet and the airflow outlet is also crucial, as this orientation regularly dictates the flow direction of both the exhaust air stream and the airflow downstream of the respective outlets. Furthermore, the orientation of the respective outlets must be such that at least a portion of the exhaust air stream and the airflow overlap, thereby increasing the volume flow of the exhaust air stream through the airflow.

[0029] Since the flow behavior of the exhaust air stream and the air stream downstream of the exhaust air stream outlet and the air stream outlet is significantly influenced by the volume flow of both streams, it may be necessary to adapt the arrangement and orientation of the exhaust air stream outlet and the air stream outlet to the volume flow.

[0030] In general, accelerating the exhaust airflow refers to an increase in the volumetric flow rate of the exhaust air compared to a non-accelerated exhaust airflow. The volumetric flow rate can be measured, for example, using flow meters. Preferably, the volumetric flow rate is determined using a non-contact flow meter, such as an ultrasonic flow meter. This has the advantage that the flow meter is not contaminated by dirt, odors, and pollutants carried in the exhaust airflow. Alternatively, the volumetric flow rate can also be determined based on the rotational speed of a fan in the respective blower system.

[0031] The effect of accelerating the exhaust airflow can be easily verified if, given the arrangement and orientation of the exhaust airflow outlet and the airflow outlet, the airflow blower system is switched off so that the airflow is no longer accelerated and thus an acceleration of the exhaust airflow is also prevented.

[0032] The acceleration of the exhaust airflow can be used to draw the exhaust airflow from a room area, especially through a fume hood, into the exhaust airflow inlet.

[0033] According to the invention, the system comprises at least one exhaust air blower system for drawing in and accelerating the exhaust air stream. The exhaust air blower system thus allows for control and / or regulation of the exhaust air volume flow. Furthermore, consistently higher exhaust air volume flows can be achieved when the exhaust air stream is accelerated by an exhaust air blower system, allowing the exhaust air stream to be directed further away from the exhaust air outlet.

[0034] According to the invention, the system comprises a control unit which is configured to control the airflow blower system and / or the exhaust blower system in such a way that the volume flow of the airflow at the airflow outlet is higher than the volume flow of the exhaust airflow at the exhaust air outlet.

[0035] An acceleration of the exhaust airflow is also achieved when the volume flow rate of the incoming airflow at the air outlet is lower than the volume flow rate of the exhaust airflow at the exhaust outlet. The best results are obtained when the volume flow rate of the incoming airflow is 80 to 400% of the volume flow rate of the exhaust airflow. With such large volume flow rates and resulting velocity differences between the incoming airflow and the exhaust airflow, the latter is carried along by the incoming airflow, and disruptive emissions of the exhaust air in the vicinity of the exhaust outlet are prevented, also due to the significant dilution.

[0036] The control of the volume flows can be based in particular on an output signal from a detector, especially a non-contact flow meter.

[0037] According to the invention, the airflow outlet is formed by an annular gap and / or nozzle ring that at least partially surrounds the exhaust airflow outlet.

[0038] In cases where the airflow outlet includes an annular gap that at least partially surrounds the exhaust airflow outlet, a particularly uniform acceleration of the exhaust airflow can be achieved. It is especially preferred if the exhaust airflow outlet and the annular gap forming the airflow outlet are concentric to each other and / or aligned such that the airflow and the exhaust airflow exit from their respective outlets parallel to each other. This can be achieved, for example, by aligning the cross-sections of the airflow outlet and the exhaust airflow outlet parallel to each other.

[0039] A parallel airflow and exhaust airflow means that their mean flow direction differs from each other by less than 10°, in particular less than 5°.

[0040] If, alternatively or additionally, the airflow outlet includes a nozzle ring that at least partially surrounds the exhaust airflow outlet, more complex airflow profiles can be formed, which accelerate the exhaust airflow. In particular, the nozzle ring comprises several nozzles, preferably uniformly arranged on an elliptical path around the exhaust airflow outlet, whereby the center points of the exhaust airflow outlet and the elliptical path can coincide.

[0041] The nozzles of the nozzle ring can, for example, be directed towards a common point located behind the exhaust air outlet in the direction of flow, so that the airflow directly hits the exhaust air stream downstream of the exhaust air outlet and thus accelerates the exhaust air stream.

[0042] It is also possible that the nozzles are oriented so that the airflow exits the nozzles tangentially to an imaginary extension of the exhaust air outlet. In particular, this can potentially create a spiral airflow around the exhaust airflow, which accelerates the exhaust airflow. This allows the exhaust airflow to be enclosed by the airflow itself, thus shielding it from the surrounding environment.

[0043] It is particularly advantageous if the nozzles of the nozzle ring are designed to be movable, so that the direction of the airflow leaving the respective nozzle can be adjusted.

[0044] Depending on the specific circumstances, the airflow outlet may be located before or after the exhaust airflow outlet when viewed in the direction of the exhaust airflow.

[0045] If the airflow outlet is located upstream of the exhaust airflow outlet when viewed in the direction of the exhaust airflow, a relatively robust embodiment of the system can be achieved with respect to the orientation of the airflow outlet, since the area between the airflow outlet and the exhaust airflow outlet can be used to achieve an optimal airflow for accelerating the exhaust airflow. For this purpose, for example, an airflow baffle plate, particularly one with a cylindrical shape, can be used, which can elliptically enclose at least part of both the exhaust airflow outlet and the airflow outlet.

[0046] A retrofit kit for existing kitchen exhaust systems with a system described above makes it possible to retrofit the system according to the invention to existing kitchen exhaust systems without modifying the existing kitchen exhaust system in the interior.

[0047] A procedure for ventilating interior spaces, especially kitchens or cooking areas, includes the following steps: i) Inflow of an exhaust air stream, in particular through an exhaust air stream inlet, from an interior space, in particular a cooking area, and discharge of the exhaust air stream through an exhaust air stream outlet, ii) Drawing in and accelerating an airflow from a second area, in particular an ambient area, using an airflow blower system, and releasing the airflow through an airflow outlet, wherein the iii) The discharge of the exhaust air stream and the air stream is carried out in such a way that an acceleration of the exhaust air stream downstream of the exhaust air stream outlet is achieved by the air stream.

[0048] In a preferred embodiment, the method comprises drawing in and accelerating the exhaust air stream with at least one exhaust air blower system, wherein in particular the acceleration of the air stream is adapted to the acceleration of the exhaust air stream.

[0049] It is further preferred if the acceleration of the airflow and / or the exhaust airflow is adapted to the wind speed and / or direction.

[0050] In another preferred embodiment, the volume flow rate of the airflow at the airflow outlet is greater than the volume flow rate of the exhaust airflow at the exhaust airflow outlet.

[0051] It is preferred if the airflow is discharged parallel to the exhaust airflow and / or in a spiral pattern around the exhaust airflow. In this way, the exhaust airflow can be enclosed by the airflow and shielded from the surroundings.

[0052] In addition or as an alternative, the airflow can also be directed towards the exhaust air stream. This causes the airflow to meet the exhaust air stream, significantly diluting the concentration of the emissions and accelerating it away from the emission source.

[0053] The invention is explained in more detail below with reference to an exemplary embodiment and the drawings. All features described and / or illustrated constitute the subject matter of the invention in themselves, irrespective of their compilation in the claims or their cross-references.

[0054] They show schematically: Fig. 1: a system for a kitchen area, Fig. 2: an exhaust air outlet and an air outlet designed as an annular gap with parallel flow direction of exhaust air stream and air stream, Fig. 3: an exhaust air outlet and an air outlet designed as a nozzle ring with parallel flow direction of exhaust air stream and air stream, Fig. 4: an exhaust air outlet and an air outlet designed as a nozzle ring with a spiral flow direction of the airflow, Fig. 5: an exhaust air outlet and an air outlet designed as a nozzle ring with an airflow directed towards the exhaust airflow, and Fig. 6: the flow behavior of an exhaust air stream accelerated by an airflow as it exits an exhaust air stream outlet.

[0055] In Fig. Figure 1 shows a system 1 for ventilating an interior space 2. System 1 comprises an exhaust air inlet 3 through which an exhaust air stream 4, originating above a cooking area 5, can enter system 1. The exhaust air inlet 3 can be located in a known extractor hood 3a. The exhaust air 4 is extracted from the interior space 2 and accelerated by the exhaust air fan system 6. The exhaust air 4 passes through the exhaust air duct 7 to an exhaust air outlet 8 and is released into the environment outside system 1 and the interior space 2.

[0056] System 1 comprises an airflow inlet 9 through which an airflow 10 is drawn into system 1. For this purpose, an airflow blower system 11 is used, which accelerates the airflow 10 along the airflow duct 13 towards an airflow outlet 12.

[0057] System 1 further comprises a control unit 14, which is designed to control and regulate the performance of the airflow and exhaust air blower systems 11 and 6. This preferably occurs in response to signals received from the detectors, which are output to the control unit 14 via the signal lines 16. The detectors are designed to determine the volume flow and / or the flow rate of the exhaust air stream 4 and / or the air stream 10 in the respective lines 7 and 13, as well as downstream of the exhaust air outlet 8. A signal generated by a weather station 15 can also be output to the control unit 14, which can be used to control and regulate the performance of the airflow and / or exhaust air blower systems 11 and 6. The weather station 15 is designed to determine wind speed and direction.

[0058] Fig. Figure 2 schematically shows an exhaust air outlet 8 and an air outlet 12 designed as an annular gap 18, which is arranged concentrically to the exhaust air outlet 8. The in Fig. The two block arrows shown indicate the flow direction of the exhaust air stream 4 and the air stream 10. The flow direction of the air stream 10 is indicated by several block arrows, even though a hollow cylindrical flow profile is actually obtained for the air stream 10. In the case shown here, the flow directions of exhaust air stream 4 and air stream 10 are parallel. The distance 19 between the exhaust air stream outlet 8 and the air stream outlet 12, which is designed as an annular gap 18, must be selected such that the air stream 10 can accelerate the exhaust air stream 4 at a given volume flow rate.

[0059] In Fig. 3 A nozzle ring 20 is designed as an airflow outlet 12, wherein the individual nozzles 21 are arranged evenly on a circular path around the exhaust airflow outlet 8. As in Fig. 2 the flow direction of the airflow 10 and the exhaust airflow 4 is provided to be essentially parallel to each other.

[0060] Fig. Figure 4 shows the same arrangement of exhaust air outlet 8 and air outlet 12 or nozzle ring 20 as Fig. 3, however, the orientation of the nozzles 21 has been changed so that a spiral airflow 10 is formed, which is indicated by the change in the direction of flow of the airflow 10 leaving the nozzles 21.

[0061] Fig. Figure 5 shows the arrangement of exhaust air outlet 8 and air outlet 12 or nozzle ring 20 as shown in the Fig. 3 and Fig. 4, however, the orientation of the nozzles 21 is changed so that the airflow 10 exiting the nozzles 21 is directed towards the exhaust airflow 4 and meets the exhaust airflow 4 in a conical arrangement downstream of the exhaust airflow outlet 8.

[0062] Fig. Figure 6 illustrates a variant of the flow behavior of an exhaust air stream 4, which enters the exhaust air stream lines 7 at the exhaust air stream inlet 3, exits at the exhaust air stream outlet 8 and is subsequently accelerated by an air stream 10.

[0063] In this case, airflow 10 is discharged via airflow outlet 12 and is directed towards exhaust airflow 4. Due to the acceleration caused by airflow 10, additional mixed air is drawn in at an external mixing air intake area 22, and exhaust airflow 4 is shielded from the outside by airflow 10. Furthermore, exhaust airflow 4 is accelerated to such an extent that the exhaust air is only distributed in an area that is no longer perceptible to the surroundings.

[0064] In this case, the velocity of the airflow 10 is reduced by the intake of the mixed air, resulting in a lower acceleration of the exhaust airflow 4. At the same time, however, there is an additional dilution, thus reducing the odor nuisance from the exhaust airflow 10 in the mixed air intake area 22. Reference sign 1 system 2 Interior 3 Exhaust air flow inlet 3a Vapor extraction 4 Exhaust air flow 5 Cooking area 6 Exhaust fan system 7 Exhaust air flow duct 8 Exhaust air outlet 9 Airflow inlet 10 Airflow 11 Airflow blower system 12 Airflow outlet 13 Airflow duct 14 Control unit 15 weather stations 16 Signal line 18 annular gap 19 gap 20 nozzle rings 21 nozzles 22 Mixing air intake area

Claims

System (1) for preventing odor nuisances, in particular for a kitchen exhaust system, comprising at least one airflow inlet (9) for the entry of an airflow (10) and at least one airflow outlet (12) for the exit of the airflow (10), wherein the system (1) comprises at least one airflow blower system (11) for drawing in and accelerating the airflow (10), wherein the airflow outlet (12) is arranged and oriented towards an exhaust airflow outlet (8) such that the airflow (10) accelerates an exhaust airflow (4) exiting the exhaust airflow outlet (8) downstream of the exhaust airflow outlet (8), wherein the airflow outlet (12) comprises an annular gap (18) and / or nozzle ring (20) at least partially enclosing the exhaust airflow outlet (8), characterized in thatthat at least one exhaust air blower system (6) is provided for drawing in and accelerating the exhaust air stream (4) and that at least one control unit (14) controls the air stream blower system (11) and / or the exhaust air blower system (6) such that the volume flow of the air stream (10) at the air stream outlet (12) is higher than the volume flow of the exhaust air stream (4) at the exhaust air stream outlet (8). System (1) according to claim 1 comprising at least one exhaust air inlet (3) for the entry of the exhaust air flow (4) and one exhaust air outlet (8) for the exit of the exhaust air flow (4). System (1) according to claim 1 or 2, characterized in that nozzles (21) of the nozzle ring (20) are designed to be movable, so that the direction of flow of the airflow (10) is adjustable. System (1) according to claim 3, characterized in that the nozzles (21) of the nozzle ring (20) are aligned such that the airflow (10) exits the nozzles (21) tangentially to an imaginary extension of the exhaust airflow outlet (8). System (1) according to claim 1 , characterized in that the exhaust air outlet (8) and the annular gap (18) are arranged concentrically. System (1) according to one of the preceding claims, characterized in that the airflow outlet (12) is arranged before or after the exhaust airflow outlet (8) when viewed in the direction of flow of the exhaust airflow (4).

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