Device for the detection of the clogging of an air filter
First Claim
1. A device for detecting clogging of an air filter located in a main duct of an air treatment apparatus operating with a constant or variable air flow, comprisingan auxiliary air duct opening upstream and downstream of the air filter so as to generate in the auxiliary duct an air flow due to the head loss of the air filter, the air flow through the auxiliary duct having a velocity relative to the head loss, the auxiliary duct extending through the air filter such that the air flow through the auxiliary duct does not flow through the air filter;
- means for positioning the auxiliary duct within and in the same axial direction as the main duct;
first sensing means arranged entirely within the main duct in proximity to the air filter for providing a signal relative to the flow velocity of the air flowing through the air filter;
second sensing means arranged within the auxiliary duct in proximity to the first sensing means for providing a signal relative to the air flow velocity in the auxiliary duct; and
an electronic circuit for receiving the signals from the first and second sensing means and generating a signal representative of a limit clogging of the air filter when the air flow speeds in the main duct and the auxiliary duct are differing by a determined value corresponding to a limit head loss of the air filter.
0 Assignments
0 Petitions
Accused Products
Abstract
A device for the detection of an air filter having an auxiliary air duct opening upstream and downstream of the air filter so as to generate in the auxiliary duct an air flow due to the head loss of the air filter and having a velocity varying in accordance with the head loss; and an electronic circuit delivering from the signals of first and second sensing devices, a signal representative of a limit clogging of the air filter when the air flow speeds within a main duct and the auxiliary duct are differing by a determined value corresponding to a limit head loss of the air filter, the device being applicable to air conditioning equipments fitting automotive vehicles.
-
Citations
20 Claims
-
1. A device for detecting clogging of an air filter located in a main duct of an air treatment apparatus operating with a constant or variable air flow, comprising
an auxiliary air duct opening upstream and downstream of the air filter so as to generate in the auxiliary duct an air flow due to the head loss of the air filter, the air flow through the auxiliary duct having a velocity relative to the head loss, the auxiliary duct extending through the air filter such that the air flow through the auxiliary duct does not flow through the air filter; -
means for positioning the auxiliary duct within and in the same axial direction as the main duct; first sensing means arranged entirely within the main duct in proximity to the air filter for providing a signal relative to the flow velocity of the air flowing through the air filter; second sensing means arranged within the auxiliary duct in proximity to the first sensing means for providing a signal relative to the air flow velocity in the auxiliary duct; and an electronic circuit for receiving the signals from the first and second sensing means and generating a signal representative of a limit clogging of the air filter when the air flow speeds in the main duct and the auxiliary duct are differing by a determined value corresponding to a limit head loss of the air filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A device for detecting clogging of an air filter located in a main duct of an air treatment apparatus having a constant or variable air flow, comprising
an auxiliary air duct opening upstream and downstream of the air filter so as to generate in the auxiliary duct an air flow due to the head loss of the air filter, the air flow through the auxiliary duct having a velocity relative to the head loss; -
first sensing means arranged entirely within the main duct in proximity to the air filter for providing a signal relative to the flow velocity of the air flowing through the air filter, the first sensing means comprising an electrically conducting element positioned in the flow of air through the air filter; second sensing means for providing a signal relative to the air flow velocity in the auxiliary duct, the second sensing means comprising an electrically conducting element positioned in the flow of air through the auxiliary duct; and an electronic circuit for receiving the signals from the first and second sensing means and generating a signal representative of a limit clogging of the air filter when the air flow speeds in the main duct and the auxiliary duct differ by a predetermined value corresponding to a limit head loss of the air filter, wherein the conducting elements of the first and second sensing means are provided with a resistance having a positive or negative temperature coefficient, the electronic circuit generating the signal representative of the limit clogging of the air filter when the ratio of the values of the resistances of the conducting elements of the first and second sensing means corresponds to the limit head loss of the air filter. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A device for detecting clogging of an air filter located in a main duct of an air treatment equipment operating with a constant or variable air flow, comprising
an auxiliary air duct opening upstream and downstream of the air filter so as to generate in the auxiliary duct an air flow due to the head loss of the air filter, the air flow in the auxiliary duct having a velocity varying relative to the head loss, the auxiliary duct extending through the air filter such that the air flow through the auxiliary duct does not flow through the air filter; -
support means for supporting the auxiliary duct within and in the same axial direction as the main duct, said support means being connected to the air filter and defining an insulated portion in the air filter adjacent to the auxiliary duct;
said support means comprising a supporting body having a box-shaped front portion located external to the air filter and bearing upon the downstream face of the air filter, said front portion comprising a bottom wall having first and second apertures, the air flow through the insulated portion of the air filter passing through the first aperture and the air flow through the auxiliary duct passing through the second aperture;first sensing means arranged in proximity to the air filter in alignment with the first aperture, the first sensing means providing a signal relative to the flow velocity of the air flowing through the air filter; second sensing means arranged within the auxiliary duct in proximity to the first sensing means in alignment with the second aperture, said second sensing means providing a signal relative to the air flow velocity in the auxiliary duct; said support means further comprising a supporting plate removably housed within the front portion of the supporting body, the first and second sensing means being located substantially in the same plane in proximity to the bottom wall and being mounted on the supporting plate, said support means further comprising a cover fastened to the supporting body for enclosing the supporting plate in the front portion, said supporting plate and said cover comprising apertures aligning with the first and second apertures of the bottom wall so as to allow passage of air through the auxiliary duct of the insulated portion of the air filter; and an electronic circuit for receiving the signals from the first and second sensing means and generating a signal representative of a limit clogging of the air filter when the air flow speeds in the main duct and the auxiliary duct are differing by a determined value corresponding to a limit head loss of the air filter. - View Dependent Claims (19, 20)
-
Specification