a method for application of a silencer and a device for the application of the method in a large diesel engine

摘要

A method for utilising a silencer unit (1) attached to an exhaust tube (2) in a large diesel engine, and an exhaust gas system for applying the method in practice, in which the silencer unit (1) includes a substantially hollow, preferably cylindrical, body member (1a), inside of which a set of sound silencing porous elements can be fitted, said elements including a flow channel (5) for the exhaust gases and being arranged in successive order in the flow direction of the exhaust gases longitudinally of the body member (1a) so that the exhaust gases are let through the flow channel (5) of each element one after the other. The elements are installed inside the body member in the axial direction from one end thereof one at a time and are supported to the inner mantle surface of the body member (1a). In the flow direction upstream of the body member (1a), the exhaust tube (2) is provided with means (10) for feeding a medium containing ammonium, urea or the like reagent applicable for catalytic depuration into the exhaust gases. In addition at least one of the elements in the body member is selected so that, in a cross-sectional plane of the body member, it covers the whole flow area of the exhaust gases and provides an exhaust gases depurating, catalytic reaction especially for decreasing the NOx-content of the exhaust gases. MATH