An acoustic monitoring system for detecting a condition of an air filter, the acoustic monitoring system including: a first acoustic transducer upstream with respect to airflow over the air filter; a second acoustic transducer upstream with respect to airflow over the air filter; a third acoustic transducer downstream with respect to airflow over the air filter; a fourth acoustic transducer downstream with respect to airflow over the air filter; a control unit in communication with the first acoustic transducer, the second acoustic transducer, the third acoustic transducer and the fourth acoustic transducer; the control unit configured to determine a filter attenuation value in response to one or more SPL values measured by at least one of the first acoustic transducer, the second acoustic transducer, the third acoustic transducer and the fourth acoustic transducer.

An air filter health monitoring system includes a filter spanning an air passage for filtering solids and/or liquids out of an air flow passing through the air passage. An illuminator is positioned on a first side of the filter and directed to illuminate the filter. An illumination sensor is positioned on a second side of the filter. The illuminator and illumination sensor can each be spaced apart from the filter. The filter can be installed in a galley insert and can include a reticulated filter medium folded in a v-shape over a v-shaped grid work.

An air quality system includes an air precleaner, a filter identification component, and a control module. The air precleaner has a precleaner housing and a filter disposed inside the precleaner housing. The filter identification component is positioned within the precleaner housing at a first position and is mounted on the filter. The control module is positioned within the precleaner housing at a second position and is configured to emit an electrical field and communicate with the filter identification component via the emitted electrical field.

A powder container including a filter that separates air and powder from each other, a hopper that includes a first opening portion installed below the filter, a second opening portion that has an opening area that is smaller than that of the first opening portion, and an inclined surface that partially overlaps the filter in plan view, a container box installed so as to be detachable from the hopper, the container box containing the powder, and a detection sensor (an optical sensor) installed outside the container box so as to oppose a side surface of the container box, the detection sensor being installed near the second opening portion and near a side of the inclined surface in a lower direction.

A powder container including a filter that separates air and powder from each other, a hopper that includes a first opening portion installed below the filter, a second opening portion that has an opening area that is smaller than that of the first opening portion, and an inclined surface that partially overlaps the filter in plan view, a container box installed so as to be detachable from the hopper, the container box containing the powder, and a detection sensor (an optical sensor) installed outside the container box so as to oppose a side surface of the container box, the detection sensor being installed near the second opening portion and near a side of the inclined surface in a lower direction.

In an example, a particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. A plurality of conductors are coupled to the porous filter substrate. The plurality of conductors are approximately parallel to each other along the porous filter substrate. The particulate filter also includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive a voltage signal from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signal from the input signal source.

In an example, a particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. A plurality of conductors are coupled to the porous filter substrate. The plurality of conductors are approximately parallel to each other along the porous filter substrate. The particulate filter also includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive a voltage signal from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signal from the input signal source.

This invention is a smart face mask for air filtration with a transparent mouth-covering portion, an active air filtration system which filters both air inflow and air outflow, an environmental or biometric sensor, and a smart control mechanism wherein the operation of the active air filtration system is automatically adjusted based on analysis of data from the sensor.

A method for designing and/or controlling a filter assembly for the air supply to a turbomachine includes: calculating a current and/or an expected concentration of particles in air present at an inlet of at least one filter stage of the filter assembly as a function of a mean size of the particles; calculating a sensitivity spectrum that, depending on the mean size of the particles, indicates an extent to which a predetermined concentration of such particles has a negative effect on performance and/or on service life of the turbomachine; calculating, for at least one filter candidate usable in the filter stage and/or switchable on or off, a concentration of particles to be expected at an outlet of the filter from a concentration and filter properties of the at least one filter candidate; and calculating a quality rating from the concentration and a sensitivity spectrum.

The present invention relates to a filter unit (10) for a compressor, comprising a housing (12) with an inlet (14) and an outlet (28) for gas to be compressed, a particle pre-filter (16) arranged downstream of the inlet (14) in the flow direction of the gas to be compressed, an ultraviolet irradiation unit (22) which is configured to emit ultraviolet light and is arranged downstream of the particle pre-filter (16) in the flow direction of the gas to be compressed, and a ballast (40) which is configured and arranged to control the ultraviolet irradiation unit (22). The filter unit (10) is designed in such a way that the gas to be compressed which is fed in at the inlet (14) first passes through the particle pre-filter (16), is then irradiated by the ultraviolet irradiation unit (22) and can finally be fed to the compressor through the outlet (28). The invention also relates to a compressor comprising such a filter unit (10) and to a method for compressing breathing air using such a compressor.