engleski

Taguchi optimization of hidrodinamic conditions for copper exchange on NaX

In heterogeneous solid-liquid systems mixing needs to ensure complete solid suspension and optimal hydrodynamic conditions regarding product properties and power consumption. In order to find optimal hydrodynamic conditions for copper exchange on zeolite NaX under isothermal conditions (303 K) Taguchi L8 (4 1 2 3 ) method was used. Experiments were carried out in a glass reactor, V = 1.3 dm 3 . Suspension height, H = 0.12 m was equal to reactor diameter, d T . Mixing was performed using pitched blade turbine with four blades (D = 0.05 m). Size of zeolite particles used was in the range from 0.063 - 0.071 mm. Solutions containing copper were prepared by dissolving Cu(NO 3 ) 2 ·3H 2 O or CuCl 2 ·2H 2 O. In the first part of this work the impeller speed that ensures the state of complete suspension (N JS ) was determined by Zwietering’s visual method 1 s at 0.33 impeller off-bottom clearances (C/H) and zeolite mass m = 6.5 g in a reactor with and without baffles. Also, at all examined mixing conditions torque was measured by Lightnin LabMaster LB2 and the power consumption was determined as well. The N JS obtained was used as one of four factors for Taguchi L8 statistical method. Along with N JS , as factors, presence and absence of baffles in the reactor, blade angle of pitched blade turbine (30° and 70°) and two different solutions containing copper, were used. For experimental results obtained, Signal to Noise ratio (S/N – larger the better) were calculated and used to evaluate optimal experimental conditions. Results of Taguchi analysis showed that the most influential factor is anion (copper solution), then blade angle, impeller speed and presence of baffles as last. At optimal conditions kinetic experiment was performed and data obtained were tested with two kinetic models: Morris-Weber (diffusion based model) and Ritchie (reaction based model).

Taguchi optimization, pitch blade turbine, kinetic, ion exchange.

nije evidentirano