When silos are filled by mechanical conveyors, there is no pressure build up in silo. Though the system becomes simpler. Mechanical conveying systems such as bucket elevators and screw conveyors that fill silos in industrial plants generally have their own electrical controls with SCADA, DCS or similar systems. Implementing new silo equipment or several safety devices may require substantial effort. Depending on mechanical and electrical configuration of conveying system, a local control panel handling all silo functions might be much more convenient. Polimak silo filling control system panels have the capability of connecting to DCS or SCADA units. Start, stop, level and alarm signals can easily be transmitted between both units, providing cost efficient and practical way of implementation.
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A start signal comes from plant’s main electrical control unit to inform the silo filling control system that conveying system will start filling the silo.
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Silo control system automatically checks silo for safety.
A self test is applied on dust collector (silo top jet filter) , process air supply and silo level. If any problem is detected (high level, malfunction in jet filter), system does not allow filling, does not send confirmation signal to main electrical control unit and keeps pinch valve closed.
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If silo is not full and jet filter self test is passed, system starts operation. and sends confirmation signal.
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Silo top jet filter (dust collector) is operated.
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Confirmation signal is sent to main electrical control unit to start filling.
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Product level in the silo is continuously measured during silo filling.
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If the powdered product in the silo reaches top level, system sends signal to stop pneumatic conveying. After a definite time dust collector is stopped.
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Process values are recorded for future use
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