The main design features and elements of industrial shaft furnaces are described. It is indicated that one of the undesirable phenomena in a shaft furnace is a large temperature gradient along its height; in this regard, the processes of air mass transfer through various parts of the furnaces are considered. The relationships and limitations that determine such a negative effect as the possibility of external air diffusing into the furnace through its walls are formulated. The results can be used to increase the quality of shaft furnace designs and the applied heat treatment processes.

Keywords: electric furnaces, heat treatment, tightness, gas permeability

Constant force supports are used in all gas and oil refineries in cases where it is necessary to provide the mobility of the pipeline at the attachment points. The article discusses the algorithm for calculating the shape of the support profile details, which has a certain design. These details provide the constancy of the pipeline support vertical force when it is transferred from the compression spring to the support point. Analytical and geometrical variations of calculation are given. The article will be useful to specialists involved in the design of pipeline supports.

Keywords: movable joint, geometric calculation, variable stiffness, lisega, import substitution