Description:Complete Specification

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a filter for a reducing agent, and more specifically to a method to detect a clogged reducing agent filter for the reducing agent.

Background of the invention
[0002] SE 201750957 A1 describes a dosing system 20 for adding a reducing agent to an exhaust gas flow from an internal combustion engine 2 and comprises a storage tank 21 for the reducing agent, a pressurizing supply pump 23 arranged downstream of the tank 21 for supplying the reducing agent via at least a first filter device 26 to a first dosing unit 22 and to a second dosing unit 24. Each dosing unit 22, 24 comprises a respective dispensing device 220, 240 for the reducing agent, the first and second dosing units 22, 24 being arranged in series and the first filter device 26 being arranged upstream of the first dosing unit 22. A bypass pipe 28 comprises a flow obstruction device 280 that is arranged to connect a supply pipe 31 from the supply pump 23 upstream of the first filter device 26 with an intermediate pipe 32 between the first dosing unit 22 and the second dosing unit 24. At least a portion of the reducing agent flow is arranged to by-pass the first filter device 26 and the first dosing unit 22 via the by-pass pipe 28 in case the first filter device 26 is at least partly clogged. The dosing system is preferably included in the exhaust system 10 of a vehicle 1.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a method to detect a clogged reducing agent filter for the reducing agent in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates a method 100 to detect a clogged reducing agent filter. The method 100 comprises positioning 110 a pressure sensor in a backflow line between a tank containing reducing agent and a filter containing reducing agent and measuring 120 a pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent. The method 100 further comprises determining 130 if the filter containing reducing agent is one of clogged and not clogged based on a measurement of the pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent.

[0005] Figure 1 illustrates a method 100 to detect a clogged reducing agent filter. The method 100 comprises positioning 110 a pressure sensor in a backflow line between a tank containing reducing agent and a filter containing reducing agent. More specifically, the pressure sensor that is positioned in a backflow line between a tank containing reducing agent and a filter containing reducing agent. The pressure sensor that is positioned in the backflow line between the tank containing reducing agent and the filter containing reducing agent measures 120 the pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent.

[0006] The method 100 to detect a clogged reducing agent filter comprises determining 130 if the filter containing reducing agent is one of clogged and not clogged based on a measurement of the pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent. The method 100 further comprises determining that the filter containing reducing agent is clogged if the measurement of pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is greater than a threshold pressure.

[0007] The method 100 to detect a clogged reducing agent filter comprises determining if the measurement of pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is lesser than a threshold pressure. If the pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is lesser than the threshold pressure, it is determined that the filter containing reducing agent is not clogged.

[0008] Moreover, if the measurement of flow rate of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is lesser than a threshold flow rate as measured by a flow rate sensor, it is determined that the filter containing reducing agent is clogged. The method to detect a clogged reducing agent filter further comprises determining that the filter containing reducing agent is not clogged if the measurement of flow rate of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is greater than a threshold flow rate as measured by a flow rate sensor.

[0009] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.

, Claims:We Claim

1. A method (100) to detect a clogged reducing agent filter, the method (100) comprising:
positioning (110) a pressure sensor in a backflow line between a tank containing reducing agent and a filter containing reducing agent;
measuring (120) a pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent; and
determining (130) if the filter containing reducing agent is one of clogged and not clogged based on a measurement of the pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent.

2. The method (100) to detect a clogged reducing agent filter in accordance with Claim 1, wherein if the measurement of pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is greater than a threshold pressure, it is determined that the filter containing reducing agent is clogged.

3. The method (100) to detect a clogged reducing agent filter in accordance with Claim 1, wherein if the measurement of pressure of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is lesser than a threshold pressure, it is determined that the filter containing reducing agent is not clogged.

4. The method (100) to detect a clogged reducing agent filter in accordance with Claim 1, wherein if the measurement of flow rate of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is lesser than a threshold flow rate as measured by a flow rate sensor, it is determined that the filter containing reducing agent is not clogged.

5. The method (100) to detect a clogged reducing agent filter in accordance with Claim 1, wherein if the measurement of flow rate of reducing agent that flows from the filter containing reducing agent to the tank containing reducing agent is greater than a threshold flow rate as measured by a flow rate sensor, it is determined that the filter containing reducing agent is not clogged.