Cyclone collection efficiencies at very high temperatures

Abstract

Experimental results for gas-solid separations in a 102 mm diameter conventional cyclone operated with air heated to temperatures between 300 K and 2 000 K, are presented. Overall and fractional collection efficiencies were measured for alumina and silica having particle sizes of 100% less than 44 pm and mass median diameters of 5.0 and 10.0 pm respectively. Inlet velocities ranged from three to 42 rn/s and inlet dust loads were between 0.3 and 235 g/mi. The dust load had a strong intluence on the collection efficiency and the loading effect was stronger at high temperatures.On presente des resultats experimentaux pour les separations gaz-solides dans un cyclone conventionnel de 102 mni de diarnktre fonctionnant B I'air chauffe B des temperatures comprises entre 300 et 2 000 K. Les efficacitks de recuperation fractionnelle et globale ont t t C mesurees pour des alumines et des silices ayant des tailles de particules h 100% inferieures a 44 pm et des diametres moyens massiques de 5,O et 10.0 pm, respectivement. Les vitesses d'entree varient entre 3 et 42 rn/s et les charges de poussieres d'entree entre 0,3 et 235 g/m'. La charge de poussikres a une grande influence sur I'efficacitC de rCcupCration et I'effet de charge est plus grand h temperatures ClevCes.

Evaluation of cyclone geometry and its influence on performance parameters by computational fluid dynamics (CFD)

“…A tight convergence criterion could be achieved using these conditions. Table 1 shows the geometric properties of the cyclone used by Patterson and Munz (1989). It was the starting point for this study.…”

“…Figure 1 shows the cyclone described in Table 1. Figure 1: Basic cyclone proposed by Patterson and Munz (1989).…”

“…Starting from the geometry proposed by Patterson and Munz (1989), some modifications of this geometry that were proposed in the literature (Zhao et al, 2004) were added. The first was the creation of a symmetrical tangential inlet by splitting the inlet into two opposite ones, and the second was the substitution of inlet and outlet ducts by volute ones.…”

“…All other cyclone parameters were maintained unchanged. The study was carried out using Patterson and Munz (1989) as reference to validate the model proposed in this work.…”

“…The starting point was based on some works available in the literature (Patterson and Munz, 1989;Zhao et al, 2004 andBernardo, 2005). Numerical simulations of gas-solid flow phase were carried out using CFX 5.7.1, a CFD code available on the market.…”