EMOS® FOR SAFE OPERATION OF ELECTROLYTIC CELLS
It is only through the precise measurement and analysis of the voltage-current-time relationship of every individual cell that the earliest possible detection of all probable electrolyser malfunctions can be achieved. Hazardous situations can consequently be avoided by enabling an emergency shutdown of the individual power supply thus preventing irreversible damage to equipment and/or personal injuries.
Most of the global players in the chlor-alkali and chlorate industry trust EMOS® for the safety of their membrane cell room.
However, these technologies are also more sensitive. Many incidents have happened worldwide after changing from the previous “workhorse” cells to the current “race horse” cells.
Traditional monitoring systems
A voltage deviation system (EDI), or Balance Voltage Monitoring System (BVMS) as it is also called, is the traditional method of providing protection to membrane electrolysers. The EDI (or BVMS) measures the voltage difference between (2) halves of the electrolyser. If the voltage difference is greater, or lower, than a certain set value, the EDI (or BVMS) will automatically shut down the power source of the electrolyser.
The EDI (or BVMS) lacks the capability of individual cell performance analysis and safety; its large voltage measuring range is prone to excessive noise, preventing it from providing adequate detection limits.
A BVMS cannot protect against the worst incidents (membrane ruptures and short circuits) because the voltage decrease of a problematic cell is compensated by the voltage increase of neighbouring cells. The total voltage change of the group of cells is then too small to be detected.
EMOS® Unique Approach to Safety
EMOS® has been designed to provide the most precise individual element voltage measurement available for electrolytic cells (±1.5mV). Hardwired interlock functions have been integrated into EMOS® in order to shutdown an electrolyser independently from the plant network and with a response time of less than 1 second in case of a spontaneous malfunction of any individual cell.