Optimization for vacuum belt drying process of Radix Salvia Miltiorrhiza extract / 中草药

ABSTRACT

Objective To select the optimum conditions of the vacuum belt drying process of Radix Salvia Miltiorrhiza(RSM) extract.Methods The process was studied by using orthogonal test design and grading method for multi-index on the parameters of the water content of dried product and drying rate of RSM extract,the average quantity of vapour during unit time span,as the index.Results The optimum process determined by the grading method was listed as follows: water content of the extract before drying was 40%,the feeding speed was 1.5 mL/s,the belt speed was 5 cm/min.Conclusion This technology can increase the average quantity of vapour during unit time span and the drying product has high quality with lower water content and desirable drying rate.