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НаименованиеA modern automated control system for dangerously explosive processes

 

The engineers at the FNPTS Altai have developed a control system for equipment placed in hazardous areas. The system is intended for industries dealing with large amounts of dangerous multicomponent mixtures, where a stringent control of process parameters is necessary.

The commercial version of the system serves equipment placed in hazardous areas zone 1 (according to the IEC classification). At the sites control instrumentation is mounted, the temperature may rise to +50°C and the humidity, to 90%. Therefore, the associated hardware withstands severe operating conditions and can be placed in special cabinets.

Central to this system is an Advantech IPC-610 industrial computer. It receives signals from more than 100 sensors and switches the relays specifying the state of actuators according to a given algorithm. Grayhill modules are used as elements of solid-state relays and galvanic insulation.

Intrinsically safe circuits of the sensors incorporate Peppel+Fuchs multichannel intrinsic safe barriers. Electrical connections inside the cabinets are made using WAGO terminals.

The possibility of smoothly varying the rotation frequency of the motors providing double-motion paddle mixing allows for shock-free start-stop control of the mixer with a moment applied to the shaft remaining constant, which is of great importance in work with explosive components.

A mnemonic is used to visualize the state of process equipment and display the values of the parameters controlled in real time. The rate of check tasks (2Hz) allows the system to respond to out-of-order situations. The system generates and stores the protocol of mixer operation, which is printed by operator's demand.

The safety of the system is additionally improved by "cold" redundancy of its basic units, as well as by combining remote and local control.

The design and introduction of the control system took four months. As a result, the throughput of the mixer has increased twofold.

The mixer configured with this control system is available in three modifications differing in throughput. It can be applied in production of industrial explosives and in chemical and pharmaceutical industries dealing with explosively dangerous substances.


Mixer

Arrangement of the instrumentation in two cabinets

By Aleksandr Zharkov, Mikhail Potapov, Leonid Zvolskiy,
Boris Levin and Yevgeniy Vostroknutov

Aleksandr Zharkov,  Mikhail Potapov,  Leonid Zvolskiy,  Boris Levin,  Yevgeniy Vostroknutov