Study On The Performance Of New Structured Packings

The metal gauze structured packings are widely used in many distillation processes because of the low pressure drop and high numbers of theoretical plate. To provide the fundamental data for the industrialization of boron isotope separation, experiments were carried out to investigate the performance of CDG1700Y and CDG2500Y metal gauze structured packings using the mixture of cyclohexane-n-heptane and n-heptane–methylbenzene under the conditions of total reflux and different reflux ratios. Experimental results show that the pressure drop rises with the increase of reflux ratio and the adverse change trend happens for the height equivalent to theoretical plate. In addition, the two kinds of packings have high numbers of theoretical plate and narrower range of operation.On the basis of experiments, SRP (II) model was used to calculate the HETP and pressure drop of CDG1700y and CDG2500Y metal gauze structured packings in order to provide reliable data for design of boron isotope separation. Comparing with experimental results, pressure drop and the HETP have the mean error percentage of 37.02 % 35.87 % 21.06 % and 20.37% respectively for the CDG1700y and CDG2500Y in the cyclohexane-n-heptane. The mean error percentage of pressure drop and the HETP in the n-heptane–methylbenzene is 26.94%,19.79%,25.45%and 21.82%.New theoretical assumptions based on the SRP (II) mode and parameters,α_g andα_l related to liquid resistance, were put forward and HTU equitation was modified. Good fits were found using lest- squares procedure and experimental results. Results using new model show that in cyclohexane-n-heptane test mixture, simulation results of CDG1700Y and CDG2500Y metal gauze structured packings have mean error percentage of 11.5% and 15.8% for HETP. In the n-heptane–methylbenzene test mixture, simulation results of CDG1700Y and CDG2500Y metal gauze structured packings have mean error percentage of 14.39% and 14.66% for HETP. All these show that the new model has better simulation results and the model is reliable.According to experimental results, the chemical exchange distillation column was designed for the separation of boron 10 and boron 11, and height of packings, inner diameter of column and pressure drop of column were determined.