## 4 Conclusions  
Thus, on the basis of the results of the study, the below conclusions can be drawn.  
The simplest, most technologically advanced, and most economical activator in operation is a blade activator that operates at a wider range of speeds than propeller and turbine activators and is suitable for mixing foam concrete mixtures with a density from 250 to 1100 kg/m\({}^{3}\).  
Figure 17: Homogeneity coefficient of mixture \(K_{chm}\) vs. inclination angle of activator blades \(\alpha_{l}\) (experimental data).  
Figure 18: Influence of the angle of inclination \(\alpha_{l}\) on the power consumption factor \(k_{N7}\) (experimental data).  
The ratio of the height of the foam concrete mixture in the mixer to the mixer diameter \(H_{mix}\)/\(D\) is optimal for foam concrete mixtures within values in the range of 0.75-1.  
A high-qualitative (homogeneous throughout the volume) foam concrete mixture with lower energy consumption can be obtained with a \(b\)/\(D\) ratio in the range of 0.04-0.06; an increase in the number of reflective partitions leads to an increase in the mixture homogeneity and an increase in power consumption for its preparation. At the same time, an increase in the number of partitions to more than four does not lead to a significant increase in power consumption and an increase in the quality of the mixture. Therefore, it is optimal to install four reflective partitions in the mixer.  
The optimal angle of the conical part of mixer \(\alpha_{cone}\) in mixers for the preparation of aerated concrete is from 50\({}^{\circ}\) to 60\({}^{\circ}\).  
An increase in the number of blades to three significantly increases the homogeneity of the prepared mixture, while a further increase in the number of blades leads to an insignificant increase in the homogeneity of mixture. Therefore, from the viewpoint of the quality of mixture prepared and from the viewpoint of the manufacturing technology of activator construction, the optimal number of blades is \(Z_{m}=3\).  
The choice of the ratio of the mixer diameter to the activator diameter should be made taking into account the power consumption and the homogeneity of mixture prepared. Therefore, it was established that the range of optimal values of the parameter \(D\)/\(d_{a}=4\)-6.  
The optimal ratio of the length to the width of blade, which ensures the maximum homogeneity of foam concrete mixture at the optimal values of the power factor, is in the range of 0.35-0.45.  
The obtained experimental data on the influence of the inclination angle of the activator blades on the quality of foam concrete mixture and the efficiency of mixing show that the optimal angle of the blade inclination is in the range of 30\({}^{\circ}\)-45\({}^{\circ}\).  
Conceptualization, S.A.S. and E.M.S.; methodology, S.A.S., E.M.S., and A.I.S.; formal analysis, A.I.S., and E.M.S.; investigation, A.Y.P., and S.M.M.; writing--original draft preparation, S.A.S., E.M.S., A.Y.P., and S.M.M.; writing--review and editing, I.A.P. and A.V.C. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the grant from the Ministry of Science and Higher Education of Russia supported by Southern Federal University, grant No. VnGr-07/2020-04-IM.  
The authors acknowledge the support by the Southern Federal University, grant No. VnGr-07/2020-04-IM (Ministry of Science and Higher Education of Russia).  
The authors declare no conflict of interest.