Characterisation of Sodium Aerosol in Cover Gas Region of SILVERINA Loop

Abstract

Sodium aerosols are continuously being generated in the cover gas region of Sodium cooled Fast Reactor (SFR) from the hot sodium pool and they play major role in heat and mass transfer to the roof top plug and side walls. In order to characterize the sodium aerosols, a study has been initiated by conducting experiments in one of the sodium loop facility SILVERINA of IGCAR. This paper describes design and installation of aerosol sampling system in SILVERINA loop, results and analysis of sodium aerosol characteristics, measurement of temperature profile of cover gas region, theoretical simulation of sodium aerosols mass concentration for the given pool (loop) condition and validation of the model with experimental results.The sodium aerosol size distribution in cover gas region is found to be mono-model. The Mass Median Diameter (MMD) of sodium aerosol is found to be varying from 1.5-11.5 µm as a function of sodium pool temperature and found to increase linearly with increase of sodium pool temperature. The sodium aerosol mass concentration is found to be varying from 0.026-35.6 g m -3 as a function of sodium pool temperature and it is found to follow 3 rd order polynomial regression with increase of sodium pool temperature. The sodium aerosol mass concentration and MMD are found to be higher near the sodium pool compared to middle of the cover gas region and near the roof top. A theoretical simulation has been carried out to predict the sodium aerosol mass concentration with respect to pool temperature for a given geometry of the vessel and the theoretical and experimental mass concentration of sodium aerosols found to have good agreement.

Studies on Geometrical Effect on Sodium Aerosol Characteristics in Cover Gas Region

“…A theoretical simulation has been developed to predict the sodium aerosol mass concentration in cover gas region by taking input from experimental value of sodium aerosol diameter and dimension of cover gas region of TP-1. A good agreement has been observed for the sodium aerosol mass concentration between theoretical prediction and experimental measurements (Kumar et al, 2015a).…”

“…A detailed description on SILVERINA Loop system with test pot-1 (TP-1), sampling system and experimental procedure are described in our earlier work (Kumar et al, 2015a). In this paper, a brief note on test pot-3 (TP-3), sampling system and experimental procedure pertaining to current experiments are given in the following section.…”

“…The study began by sampling metal aerosol without exposing to atmosphere in Aerosol Test Facility (ATF) and characterization techniques is validated in SILVERINA Loop (Kumar et al, 2014), followed by, experimentation in TP-1 of SILVERINA loop to determine sodium aerosol mass concentration and size distribution for various pool temperatures (250-550°C). The salient results of the experiments are summarized as: (i) the mass concentration in cover gas region is found to vary in the range of 0.026-35.6 g m -3 and the MMD is found to vary in the range of 1.5-11.5 µm for pool temperature 250-550°C respectively, (ii) the sodium aerosol mass concentration increases with increase of sodium pool temperature according to polynomial function and the MMD of sodium aerosol increases linearly with increase of sodium pool temperature, (iii) the mass concentration and MMD of sodium aerosol is found to be larger near the pool surface than near the top flange and middle region of cover gas (Kumar et al, 2015a). The temperature profile of the cover gas region was measured at various heights viz.…”

“…[The detailed description of the above systems is described in our earlier work (Kumar et al, 2015a)]. In the present experimental set-up, the portion of the sampling tube which goes inside TP-3 has been fabricated with a length of 385 mm to enable the sampling at the middle level.…”

“…The pool, roof and bulk cover gas temperatures are important parameters for the theoretical simulation of aerosol mass concentration in cover gas region of SILVERINA loop. Hence a similar type of temperature measurement system as described in Kumar et al (2015a) for TP-1, has been fabricated with matched top flange for the aerosol port. It consists of vertical cylindrical shaft welded below the top flange with six grooves to insert 6 thermocouples which are terminated at six different heights.…”