In this work, the combustion process of chromium powder in the co-flow filtration mode was studied. The effect of nitrogen-containing gas flow rate on the nitridation of combustion products is shown. The effect of the amount of argon in the nitrogen–argon mixture on the burning rate and the burning temperature of the chromium powder is shown. It was found that an increase in the percentage of argon in the nitrogen–argon mixture can lead to the formation of an inverse combustion wave. The actual burning temperature is higher than adiabatic burning temperature in the co-flow filtration mode, thus the phenomenon of superadiabatic heating is observed. The phase composition of the obtained combustion products was studied. It was shown that the forced filtration mode allows for synthesizing non-stoichiometric Cr2N nitride.

This paper explores different modes of synthesis by combustion of chromium-nitrogen and ferrochromium-nitrogen alloys. The SH-synthesis of chromium nitrides and ferrochromium nitrides was performed. Regular patterns in layer-by-layer and surface modes of Cr combustion in nitrogen were investigated. The mechanism of non-stationary combustion during the synthesis of chromium was investigated. Regular patterns of chromium and ferrochromium combustion in the cocurrent filtration mode were analyzed, and the possibility to intensify the SHS process using the pressure filtration principle was assessed. The process of chromium powder combustion in the cocurrent flow of nitrogen-containing gas in the range of specific flow rates from 20 cm3/s·cm2 was investigated. Pressure filtration intensifies the process of combustion wave propagation in the Cr–N2 system. Here, the combustion rate increases while the degree of nitridation decreases. We discovered superadiabatic heating modes when the reaction zone was blown with pure nitrogen and a nitrogen-argon mixture. The tempering mode that was realized during pressure filtration allows for the uptake of high-temperature single-phase non-stoichiometric phases of Cr2N.

The authors have developed electric regulators: relay-pulse ones, with solid filler and electric heater, with solid filler and thermoelectric module, for a heat exchanger to obtain the energy of the water-ice phase transition. Experimental studies were carried out, the static and dynamic characteristics of electrical controllers were determined to determine the most fast-acting regulator. They substantiated that after the use of the thermoelectric module, the regulator operation is ensured during potato storage heating and cooling. Moreover, when they change the potato storage operating modes by changing the polarity of the thermoelectric module, the speed of the regulatory body is ensured. The heating efficiency of the solid-filled electrical regulator and thermoelectric module is higher than of electrical regulator with solidfilled electrical controller and electric heater.