DE202012012682U1 - Aerotoxic filter - Google Patents

Abstract

Device for filtering an air mixture with particles and gaseous impurities comprising at least two filter modules (100, 200), which are arranged behind one another for filtering the air mixture, wherein the first filter module (100) for separating particles and / or for expelling smallest particle masses the air mixture is provided by two, in particular concave deflection surfaces (111, 112, 121, 122), which swirl the air mixture, and wherein the second filter module (200) for separating the gaseous impurities of the air mixture is provided by hoses (201), the surface of a liquid film is wetted with a washing liquid to form a reaction surface for mass transfer between the washing liquid and the air mixture flowing around the tubes (201), thereby effecting purification of at least gaseous impurities from the air mixture.

Description

FIELD OF THE INVENTION

The present invention relates to an aerotoxic filter, which is used in particular in aircraft, for filtering an air mixture with particles and gaseous impurities with at least two filter modules and a method for filtering an air mixture with particles and gaseous impurities.

BACKGROUND OF THE INVENTION

In almost all commercial aircraft, the fresh air for the cabin is removed by means of a tap system from the compressor of the engine. In particular, older or poorly maintained commercial aircraft may fail to seal the bearings in the compressor, e.g. due to porous or cracked seals or incorrectly applied seals. This allows oils or oil vapor to enter the engine's airflow, from where it can enter the cabin via the dispenser.

In engines lubricated with special oil, heavy heating of the special oil can give rise to toxic gases that may get into the cabin air. Among other gases such as organo-phosphates, phenyl naphthylamine tricresyl phosphate (TCP) can arise. The health damage caused by the contaminated air in the cabin is also discussed under the term "aerotoxic syndrome".

Due to the small installation space, the constant weight reduction in airplanes and the strong cost pressure to which the aircraft manufacturers are exposed, filter systems in airplanes are not provided.

Therefore, it is an object of the present invention to solve the above-described disadvantages. In particular, it is an object of the present invention to provide a device which economically and reliably keeps the cabin air free from contaminants and toxic gases and yet is simple in design and easy to maintain.

SUMMARY OF THE INVENTION

The object is achieved by a device for filtering an air mixture with particles and gaseous impurities with the features of independent claim 1 and by a method for filtering an air mixture with particles and gaseous impurities having the features of independent claim 15. Advantageous embodiments are particularly apparent the subclaims following the independent claims.

The inventive device for filtering an air mixture with particles and gaseous impurities has at least two filter modules or modules, which are arranged one behind the other, so that the air to be cleaned can pass through both filter modules. Preferably, the filter modules are arranged in a housing which is hermetically sealed from the environment and has only an air inlet and an air outlet, in order to flow through the air to be filtered. Advantageously, the filter modules are interchangeably arranged in the device, e.g. by means of a rail system, with which the filter module can be pulled out of the device for maintenance purposes or to replace the entire filter module and pushed back into it. The filter modules can be locked in the device with quick fasteners, such as snap, click or snap connections, or by means of a screw connection. Furthermore, the filter modules can be arranged in the housing such that it is ensured that the entire air flowing into the device is cleaned. However, the entire apparatus and filter modules must meet the requirements of aviation, i. that the filter modules must withstand predetermined shocks and vibrations and must be resistant to heat and cold. This can be done by a stable, in particular double-walled housing and optionally by buffer elements at the attachment points of the device and the filter modules to reduce the vibrations and vibrations.

In order to be able to comply with any prescribed or statutory limit values, the filter device may also comprise two, three or more filter modules of the first filter module and / or second filter module. In particular, in the case of the second filter module, different impurities can be washed out of the air mixture by different washing liquid, so that a contaminant can be filtered from the air mixture in a targeted manner with a filter module. Preferably, the aerotoxic filter is able to humidify the air mixture, which is particularly important for passenger cabins of aircraft of particular importance, since the cabin air is mainly dry, which is unpleasant for the passengers.

Further, it is advantageous if the device is small in size, in order not to unnecessarily consume the without small space in an aircraft unnecessarily. Another advantage of a small device is that it can be retrofitted into existing systems, as due to the size of easier space in existing Aircraft types is to be found. Preferably, the device with filter modules is between 30 cm and 80 cm high and between 30 cm and 80 cm wide. A filter module can be between 20 cm to 70 cm high and between 20 cm to 70 cm wide. An optimal filter module dimension would be 30 cm by 30 cm. The depth of the filter module depends on the number of existing filter modules.

The device for filtering an air mixture with particles and gaseous impurities may, in principle, be arranged at any point between the engine and the cabin. It is advantageous, if the device is arranged in the line directly after the engine, directly in front of the device for air conditioning the cabin air, directly after the device for air conditioning the cabin air or directly in the circuit of an aircraft toilet or the cabin can be attached. In a cabinet-near arrangement better maintainability or interchangeability is ensured because the maintenance personnel can get from the aircraft interior to the device and only the inner lining must be removed. It is also possible that a plurality of filter devices, even with different throughput and / or number of filter modules, be mounted in a circuit and / or throughout the aircraft.

The filter device should be capable of a throughput between 300 m ³ / h to 900 m ³ / h, in particular 600 m ³ / h to accomplish. At a flow velocity between 1 m / s and 4 m / s, in particular between 2m / s and 3m / s, operation of the filter device is possible. The flow resistance is between 150 Pascal and 300 Pascal.

One of the filter modules arranged in the device according to the invention, preferably the first acted on, is the filter module for separating particles from the air mixture. In the air mixture, which is derived from the engine, pollutants in the form of aerosol, mist or vapor with particles in the micron range. The particles have a predetermined mass, which can be deposited or expelled by turbulence, breaks and by means of cyclone action. In the following, the flow direction of the air mixture to be filtered is regarded as the direction which the air mixture has from the line coming from the engine.

The first filter module has at least one filter module unit which has two concave deflection surfaces which are arranged substantially longitudinally to the flow direction of the air mixture. The inner surfaces of the concave deflection surfaces can be arranged opposite one another. Furthermore, the concave deflection surfaces can be arranged offset in length from each other, so that the air mixture is guided by the front concave deflection surface on the rear concave deflection surface, preferably centrally on the rear deflection surface. The air mixture can reach or be guided essentially obliquely to the flow direction into the filter module unit. The term "oblique" in this application defines an angle range between 10 degrees and 80 degrees with respect to the direction of flow, preferably an angle of 30, 35, 40, 45, 50, 55, 60, 65 or 70 degrees, with an angle therebetween located angles are not excluded. The arrangement of the concave deflection surfaces to each other forms in the center of this a chamber in which the air mixture rotates and swirls. The rear concave diverting surface directs the air mixture to the outlet of the filter module unit. Preferably, the air mixture leaves the filter module unit at an oblique angle with respect to the flow direction. It is particularly preferred if the air mixture flows both obliquely into the filter module unit and flows out obliquely out of the filter module unit, so that in particular the inflow direction and the outflow direction are parallel.

Preferably, the first filter module has two mirror-image mutually arranged filter module units each with concave deflection surfaces, as described above. Due to the mirror-image arrangement, the outflow directions of the respective filter module units can be directed towards each other, so that the air mixture streams of adjacent filter module units meet and again generate turbulences and thereby deposits.

The filter effect is achieved in the first filter module in that both the inflow of the air mixture at an oblique angle to the flow direction and in the chamber between the concave deflection surfaces, the air is exposed to turbulence, causing the Vorabscheidungen of the particles. In addition, in the chamber between the concave deflection surfaces there is an expulsion of the smallest particle mass due to the cyclone effect. In the case of an arrangement of two filter module units arranged in mirror image relative to one another, there is additionally a deposition of very small particles in the meeting of the air mixture streams during the outflow of the air mixture of adjacent filter module units, which are respectively directed obliquely to the direction of flow and toward one another.

Preferably, the deposition rate in the first filter module is about 95% with a particle size of less than 5 microns.

The first filter module is particularly advantageous since it has a simple construction of only two Has concave deflection per filter module unit, whereby a favorable production can be ensured. Furthermore, the structure allows a high flow rate, since the flow resistance is only between 250 Pascal and 350 Pascal. As a result, the filter module is particularly suitable for use in aircraft, in which the air mixture is discharged from the turbine.

The filter technology of the second filter module is based on a modified, wet-mechanical and / or wet-chemical deposition. For this purpose, hoses are used, which are preferably permeable to gas and liquid and consist of polymers and in particular are arranged perpendicular or along the force of gravity. The hoses are made stable and porous by a special thermal treatment. Due to this structure, a liquid film can be produced on the surface of the tubes, which represents the reaction surface for the mass transfer. Between 1800 hoses and 2500 hoses can be installed per filter module, in particular 2050 hoses. In a preferred filter module size of 30 cm by 30 cm, an effective area of 20 m ² to 30 m ² , in particular about 24 m ² , are present. The inflow temperature can be between 150 degrees C and 200 degrees C, with preferably 170 degrees C is provided as the maximum temperature. The flow velocity can be between 2 m / s and 3 m / s, wherein the flow resistance of the second filter module is about 200 Pascal.

In the second filter module, the washing liquid is preferably supplied to the hoses from above and, on the way down, reaches the outside of the hoses, which are wetted uniformly. Due to the special arrangement of the hoses a continuous gas turbulence and gas deflection is effected in the horizontal passage of the air mixture through the filter module, which in particular the gaseous impurities are washed out of the air mixture. The loaded or dirty washing liquid can be cleaned and reused.

Hereinafter, embodiments of the invention will be explained with reference to figures. The features disclosed in the exemplary embodiments form each individually and in each combination of features the subject-matter of the claims and also the embodiments described above.

BRIEF DESCRIPTION OF THE DRAWINGS

1 shows an aerotoxic filter in perspective with a first filter module and a second filter module for filtering an air mixture with particles and gaseous impurities;

2 shows the first filter module in perspective view;

3 shows two filter module units of the first filter module, each with two concave deflection surfaces with turbulence;

4 shows the second filter module of the aerotoxic filter;

5 shows that in 4 shown second filter module as a functional diagram;

DETAILED DESCRIPTION

1 shows an aerotoxic filter 10 with the first filter module 100 and the second filter module 200 , wherein the first filter module partially from the housing 11 of the aerotoxic filter 10 was pulled out. For the sake of clarity, this is the case 11 hermetically sealed front in 1 not shown. The filter modules 100 . 200 are on rails 12 arranged to ensure withdrawal of the filter module or a better interchangeability can. The rail system 12 runs at the top and at the bottom of the respective filter module 100 . 200 , which at the same time as attachment or locking of the filter modules 100 . 200 in the case 11 serves. Due to this attachment at the top and bottom of the filter modules 100 . 200 can the air mixture to be cleaned directly through the filter modules 100 . 200 flow without creating swirling on fastening contacts. The air to be cleaned is from the front of the aerotoxic filter 10 supplied (flow direction 1 ), in particular perpendicular to the filter module 100 . 200 , and discharged at the opposite end.

The housing 11 of the aerotoxic filter 10 is secured against vibrations and shocks so that it can be used in eg an airplane. Furthermore, the housing 11 double-walled, so that the housing 11 These bumps better buffers and possibly damage to the filter modules 100 . 200 can prevent.

The 2 and 3 show several filter module units 110 . 120 of the first filter module 100 in the aerotoxic filter 10 which are arranged side by side. Here is a filter module unit 110 next to a mirror image arranged to filter module unit 120 positioned as in 3 shown. Each filter module unit 110 . 120 each has two deflection surfaces 111 . 112 . 121 . 122 on which the incoming air from the air inlet 113 . 123 to the air outlet 115 . 125 conduct. The deflection surfaces 111 . 112 . 121 . 122 extend in a circular arc segment less than 180 degrees, but greater than 150 degrees, so that only a small deflection takes place, whereby a high air mixture flow can be passed through the filter module unit. The air mixture flows obliquely or at 50 degrees to the flow direction 1 in the filter module unit 110 . 120 into it. Subsequently, the air mixture flows into one of the two concave deflection surfaces 111 . 112 . 121 . 122 formed chamber 114 . 124 in which pre-separation of particles occurs due to turbulences and breaks. Further, in the chamber 114 . 124 smallest particle masses expelled because of the cyclone effect, as in 3 also shown. At the air outlet 115 . 125 meet the mixed air streams of the mirror image arranged adjacent filter module unit 110 . 120 each at an angle of about 50 degrees with respect to the flow direction 1 each other. The flow angle at the air inlet 113 . 123 and at the air outlet 115 . 125 is per filter module unit 110 . 120 aligned in parallel.

4 and 5 show the second filter module 200 , In 4 is the vertical filter module 200 visualized in perspective, with the hoses 201 between an upper filter module part 202 and a lower filter module part 203 are arranged. The tubes 201 are gas and liquid permeable, polymeric hoses 201 , which are porous, to absorb or absorb the washing liquid. The number of hoses 201 is 2050 pieces, which achieve an effective area of about 24 m ² . The targeted start-up speed is 2 to 3 m / s and the second filter module has a flow resistance of 200 pascals. The maximum inflow temperature is 170 degrees C.

The respective surface of the hoses 201 is wetted with a washing liquid contained in a container in the upper filter module part 202 which is due to gravity from the top of the tubes 201 to the lower end of the tubes 201 flows. Thus, a cost and extensive wetting of the tubes 201 guaranteed. The contaminated washing liquid which has cleaned the air mixture can then be placed in a container in the lower filter module part 203 be collected and cleaned for reuse.

5 shows how the mixed air flow 1 perpendicular to the second filter module 200 meets and on the other side of the filter module 200 cleaned 206 emerges. From above, the filter module 200 Supplied washing liquid 204 , which is at the bottom of the filter module 200 with impurities (loaded washing medium) is derived 205 ,

Claims (14)

Device for filtering an air mixture with particles and gaseous impurities comprising at least two filter modules ( 100 . 200 ), which are arranged one behind the other for filtering the air mixture, wherein the first filter module ( 100 ) is provided for separating particles and / or for expelling smallest particle masses from the air mixture by two in particular concave deflection surfaces ( 111 . 112 ; 121 . 122 ), which fluidize the air mixture, and wherein the second filter module ( 200 ) is provided for separating the gaseous impurities of the air mixture through hoses ( 201 ), the surface of which is wetted by a liquid film with a washing liquid to a reaction area for a mass transfer between the washing liquid and the hoses ( 201 ) represent air flowing around, whereby a cleaning of at least gaseous impurities from the air mixture is effected. Apparatus according to the preceding claim, wherein the filter modules ( 100 . 200 ) are interchangeable and / or scalable.  Device according to one of the preceding claims, wherein the device is dimensioned so compact that the device installed in an aircraft, in particular can be attached to a water circuit of an aircraft toilet. Device according to one of the preceding claims, wherein the dimension of the end face of the second filter module ( 200 ) Is 30 cm by 30 cm. Device according to one of the preceding claims, wherein the device is provided for a volume flow of 600m ³ / h. Device according to one of the preceding claims, wherein the concave deflection surfaces ( 111 . 112 ; 121 . 122 ) of the first filter module partially interlock, so that a chamber ( 114 ; 125 ), in which the air mixture passes through the deflection surfaces ( 111 . 112 ; 121 . 122 ), whereby an expulsion of very small masses of particles from the air mixture takes place. Device according to one of the preceding claims, wherein the air mixture in the first filter module ( 100 ) only by two concave deflection surfaces ( 111 . 112 ; 121 . 122 ) to be led. Device according to one of the preceding claims, wherein the air inlet ( 113 ; 123 ) of the first filter module ( 100 ) is arranged obliquely to the flow direction of the air mixture, in particular in an angular range between 20 ° and 40 ° to the flow direction of the air mixture.  Device according to one of the preceding claims, wherein the air inlet and the air outlet are arranged parallel to each other. Device according to one of the preceding claims, wherein the two deflection surfaces ( 111 . 112 ), through which the air mixture flows, a filter module unit ( 110 ), to which a mirror-image a second filter module unit ( 120 ) is arranged parallel to it and the air outlets ( 115 . 125 ) of the first filter module unit ( 110 ) and the second filter module unit ( 120 ) are directed towards each other, so that the outflowing air mixture of the two filter module units ( 110 . 120 ), causing turbulence to separate the particles of the air mixture. Device according to the preceding claim, wherein the two air outlets ( 115 . 125 ) of the two mirror-image arranged filter module units ( 110 . 120 ) coming air mixtures in an angular range of 90 ° to 180 ° meet. Device according to one of the preceding claims, wherein the hoses ( 201 ) of the second filter module ( 200 ) are permeable to gas and liquid and in particular made of polymers. Device according to one of the preceding claims, wherein the hoses ( 201 ) of the second filter module ( 200 ) have a fluid liquid flowing down by gravity of washing liquid, the surface of the tubes ( 201 ) is evenly wetted to absorb gaseous pollutants from the air mixture. Device according to one of the preceding claims, wherein the hoses ( 201 ) of the second filter module ( 200 ) are arranged vertically and are positioned relative to each other such that turbulences of the hoses ( 201 ) resulting air mixture, so that a better admission of the air mixture with the washing liquid on the surface of the tubes is formed.

Images