Maintaining railway turnout operability is crucial for ensuring railway transport safety. Electric heating of railway turnouts is a significant technical and economic issue. The classical heating is characterised by high power consumption. For this reason, research is needed to optimise the current system. This paper presents results of a numerical analysis and of experimental researches. The numerical analysis was carried out using the ANSYS software. There was conducted a numerical comparative analysis of energy loss during heating performed using two different heaters. Including the classical method and a heater thermally insulated from a rail. In the first step, heating of a working space filled with a substitute snow model was considered. The snow-covered surface area was held within the working space of the turnout. It was assumed that the snow substitute material had thermal properties approximately the same as real light snow. It was also assumed that the material is in the solid state which would not undergo a phase change. In the next step, a real snow model that included the phase change process was taken into account. The energy efficiency and heat distribution in the turnout have been analysed and compared. The experimental researches were carried out in a physical model. The results showed that the use of a contactless heater results in creating a larger area over which emitted heat affected snow in the working space. Consequently, more snow was melted around the contactless heater than the classic one. This experimental observation supported the results of the numerical analyses presented previously.
A comparative analysis of filtration performance of tangential and axial
inlet reverse-flow cyclone separators and vortex tube separators is
presented. The study showed that vortex tube separators are
characterized by a quality factor q several time higher
than tangential inlet reverse-flow cyclone separators. The cyclone
separators yield low separation efficiency and low filtration
performance at low air flow rates at low air volumes aspired by the
engine at low speed. One of the well-known and not commonly used methods
to improve separation efficiency is to apply electric field. An original
design of a vortex tube separator with insulators generating electric
field in the area of aerosol flow is presented. High voltage was applied
to the cyclone separator housing and its swirl vane. A special method
and test conditions were developed for cyclone separators with electric
field. Separation efficiency, filtration performance and pressure drop
across the cyclone separator in two different variants were determined.
The tests were carried out at five inlet velocity of cyclones υ0
= 1.75; 3.5; 7.0; 10.5; 14 m/s at an extraction rate of m0
= 10%, and at an average dust concentration in the inlet air of
s
= 1 g/m3. Using the electric field in the area of
a swirling aerosol stream resulted in an increase (over 12% – φc
= 96.3%) in separation efficiency at inlet velocity of cyclone ranging
from 1.75 to 3.5 m/s. An increase in separation efficiency at other
inlet velocity of cyclone is minor and does not exceed 3‒4%.