Patent ID: 9211501
Filing Date: 2015-12-15
Classification: B01D,F01N,Y02T

Abstract:
1. A reducing agent supply device, comprising: a selective supply unit including an air passage, an air bypass, an air control valve, a backflow prevention valve, and a flow control valve, the flow control valve having an outlet and a plurality of inlets, a reducing agent supply unit connected to a first inlet of the plurality of inlets of the flow control valve and configured to supply a reducing agent to the selective supply unit, a water supply unit connected to a second inlet of the plurality of inlets of the flow control valve and configured to supply water to the selective supply unit, a spray unit connected to the outlet of the flow control valve of the selective supply unit, the selective supply unit being configured to selectively supply any one of the reducing agent from the reducing agent supply unit and the water supplied from the water supply unit to a reducing agent passage connected to the spray unit, the spray unit being configured to spray the reducing agent or the water supplied from the selective supply unit, and an air supply unit for supplying air to the selective supply unit, the air supply unit being connected to the air passage and configured to supply air therethrough to the spray unit, the air bypass connecting the air passage to the reducing agent passage wherein the air control valve is located between the air bypass and the air passage and the air control valve is configured to selectively provide airflow therethrough, the air bypass including the backflow prevention valve configured to prevent flow of the reducing agent and the water from the reducing agent passage to the air passage, wherein the selective supply unit supplies the water to the spray unit when the spray unit is blocked due to solidification of the reducing agent which remains behind therein because of a process in which the spray unit continuously sprays the reducing agent or a temporary malfunction of the reducing agent supply device, thus preventing blockage of the spray unit.