Mathematical model and control system for chromium recycling process

Abstract

The paper deals with application of computer controlling and displaying system of the technological recycling process of both liquid and solid wastes from the tanning industry. The chrome tannery wastes are potentially dangerous to the environment. A proposal for chrome recycling technology, realization of the laboratory equipment and programming possibility are likewise presented. The idea of recycling technology lies in using reaction of non - environmentally friendly chrome liquid and solid wastes and creating new products that are not toxic and can be used in the other industrial applications. Described mathematical model for the recycling technology is based on the chemical - physical engineering description of a heterogeneous kinetics. The method of regressive analysis was used for determining of parameters for each kinetic equation from the experimental data. The proposed model was used for a simulation test and an optimum calculation in the connection with minimum procedural costs of recycling technology. The real process presentations are built with laboratory equipment for a closed recycling technology of real chrome liquid and solid wastes taken from the tanning company TAREX. The computer controlling and displaying system has two levels. The technological level is composed on a PC with the technological extension card Advantech PCL-812PG ensuring the direct control over the real process. The software for this level was created in the C language with the real time library RTMON. The supervisory level creates a personal computer with professional displaying software by Wonderware InTouch. The parts of software are DDE server module ensuring the communication between both levels of the control system via the serial link RS 232.