## 1 Introduction  
The Polish power system strongly depends on carbon power stations. Therefore, Poland is facing the problem of dust particles and high emission of greenhouse gases (\(GHGs\)). Although much research enabling the capture of carbon dioxide and the purification of flue gasses is being undertaken, the problem remains unsolved [1; 2]. In addition, syngas purification is a basic problem in the gas production process through biomass gasification [3]. However, due to the complexity of the multiphase flow and numerous physical phenomena related to them, researchers continue investigations in this area aiming at the improvement of the purification efficiency of the contaminated gas. Presently, numerous practices aiming at flue gas dedusting and its purification from chemicals are being undertaken. This topic is essential in fighting atmospheric air pollution. Gas purification from chemicals, solid particles, and biohazardous materials is of prime importance as these problems exist in many industrial branches and individual households. The Venturi nozzle consists of a converging channel, a throat, and a diverging channel. It operates as a device that is widely applied for gas dedusting and its purification from chemicals. It is an integral component of the Venturi scrubber, which is a leading device applied for gas cleaning ([2; 3; 4; 5; 6; 7]). These devices are thought to be very efficient. Additionally, the economic aspects related to their usage are also favorable. The geometric diversity of the nozzle has a significant impact on the variations in values of fluid-flow parameters, such as velocity and pressure. A highly efficient gas cleaning process can be achieved using proper nozzle geometry and an appropriate method of injecting a scrubbing liquid into the gas flow. Investigations of the physics of the fundamental issue of the annular-mist (gas-liquid) flow with the liquid film developing on the channel's wall have been dealt with for decades. The Venturi nozzle's multiphase flow problem is more intricate than that of a pipe with a constant shape, and therefore, it is more challenging to investigate. Presently, numerous research studies still raise the problem of the flow pattern being formed in the multiphase flow through the Venturi nozzle, even though it has been studied for decades. This proves that the scientific problem in question is still relevant and warrants further research. The author of the paper has carried out theoretical research that has addressed two-phase (gas-liquid) flow and a single droplet flow [1; 8; 9]. Paper [1] introduces a mathematical model that incorporates the deposition of droplets and their entrainment in the annular-mist flow in the throat section of the Venturi nozzle. The model enables the estimation of a superficial velocity of both the droplets in the mist flow and the liquid film along the throat. By employing the model, the distance at which the droplets' entrainment from the liquid film on the wall begins can be determined. The mathematical model allows for the estimation of the parameters for the mist flow in the flow's core. The results obtained are then utilized to determine the pressure drop across the Venturi throat. By the analysis of the outcomes gained, it was concluded that the distance at which the droplet entrainment commences is strongly correlated with the mass flow rates of water and air and with the diameter of the throat \(d_{th}\) of the Venturi that was expressed in meters (0.05, 0.06, 0.12, and 0.18). The alteration in mass flow rates of droplets and liquid film on the wall was found to be nonlinear, which is rather obvious. The outcomes have shown that neglecting the entrainment flux of droplets leads to the linearization of the mass flow rates of droplets and liquid film. Furthermore, it was noticed that applying a larger throat diameter \(d_{th}=0.18\) m) and throat length (\(L_{th}m\)) of less than one meter has resulted in the potential growth of dedusting efficiency.