The subject of the research was a reinforced concrete chimney with an unusual structure, the crown of which is closed by a reinforced concrete plate with a central circular confusor and  five circular openings arranged regularly in the perimeter system on the slab. The openings have flaps that are closed or opened depending on the amount of flue entering the chimney. The aim of the researchwas to evaluate the applied solution taking into account the operational possibilities given by the construction and durability of the structure. The basis for the assessment of the chimney work was the thermodynamic description of the flue gas flow through the chimney for various possible output conditions. In particular the power lines, velocity distributions and flue gas temperature in the chimney area and on the outlet were determined. On the one hand, the possibility of flexible control of the chimney work was demonstrated, on the other hand, certain constructional defects that affect the destruction of the chimney head were pointed out. Keywords: industrial reinforced concrete chimney; unusual chimney design; thermodynamic description.