In the present work, two sub regions of the dedusting of an electric arc furnace are investigated. The first part deals with the water-cooled hot gas line, which is used for cooling the extracted exhaust furnace gas to the maximum allowable operating temperature. This will ensure that the following investment segments are not damaged. In the second part follows an investigation of the sliding sleeve. It forms the connecting link between the electric arc furnace and the dust extraction system. It is also possible to adjust the amount of false air drawn in from the environment. This is necessary to supply sufficient oxygen for complete combustion. The aim of the first part is to make a conceptual comparison of two hot gas lines with different cross sections. Here, a hot gas pipe with a round cross -section, which are faced with a square cross section. The comparison is divided into three categories 1.flow technical comparison 2.structural comparison 3.cost comparison For the fluidic compare the behavior of the furnace exhaust gas in the two different hot gas lines is investigated by means of simulations, and the results are compared to each other. In order to carry out the construction comparison, a design concept for a square version of the hot gas line is being developed. The main focus of the redesign is on the reduction of transport costs. The costs of the round hot gas line are compared with those of the square redesign. The total costs are divided into three groups: •manufacturing costs •transport costs •installation costs The second part of the paper has the goal to find an elaboration of cost-effective design alternatives, compared to the existing water cooled hot gas line construction.