REDUCTANT SUPPLY SYSTEM FOR A WASTE GAS CLEANING CATALYST AND A HEATING UNIT THEREFOR

The invention relates to a reducing agent supply system for an exhaust gas purifying catalytic converter of an internal combustion engine, particularly of a motor vehicle, comprising: a reducing agent tank (3) for holding reducing agent; a connecting line (4, 5) in order to convey reducing agent from the reducing agent tank (3) to an exhaust gas purifying catalytic converter (2), and; a pump (6) for pumping reducing agent through the connecting line (4, 5) from the reducing agent tank (3) to the catalytic converter (2). The invention provides that at least one section of the connecting line (4, 5) is provided in the form of a corrosion-resistant metal pipe, which is provided with electrical connections (10, 11, 12, 13) for conducting an electrical heating current through the connecting line (4, 5) in order to thaw reducing agent. The invention also relates to a heating device for a supply system of the aforementioned type comprising a corrosion-resistant metal pipe (4), which is to be immersed into the solution, can be connected in the form of a suction pipe to a pump (6) for delivering the thawed solution, and on which the electrical connectors (10, 11) are placed in order to conduct a heating current through the metal pipe (4) that heats the metal pipe (4) in order to thaw the solution.