Electrical installation of a new processing line for category 3 material

The new addition of machinery was to be added onto an existing automation system. To achieve this, we had to install two input/output control panels. The process was split into two areas which were the tank area and the tri-canter area. An IO panel was installed locally in each area and the control circuits were wired back to their corresponding panels.

DEFRA legislation requires raw material to reach 100 degrees centigrade and be cooked under 3 bars of pressure for minimum of 95 minutes; this is to sterilise the potentially harmful biological agents in the material. To achieve this there were spring returned steam valves on inlet pipes into the tank which were operated remotely. We also installed and calibrated modulation valves which through interaction with pressure transmitters would maintain the correct pressure of 3 bar. After the DEFRA requirements are met, the material is then moved through pipework to a Flott-Weg tri-canter machine using a lamella pump and slide valves.

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All power cables for pumps and mixer motors were supplied from a control panel which incorporated variable speed drives, also known as inverters.

Flott-Weg provided the control panel for the tri-canter which had to be integrated into the system using binary control signals from analogue and digital sensors in the field which communicated with the process via two IO-panels.

The tri-canter machine is a large centrifugal device which jets the material under pressure causing it to segregate into several aspects; water, material and tallow. The separation of water from the material means less power is needed to dry the material and in turn makes this process far more efficient and cost effective.

The tallow is also diverted upon separation. This is stored in a tank which we fitted with non-contact ultrasonic level and pressure transmitters. These sensors are also incorporated into the automation system to display precise holdings of the storage tank.

Throughout the processing line we installed pneumatic actuated knife valves to control the flow of material. These valves are operated remotely by energising solenoids allowing pressurised air to function the knife; open or closed. We installed two proximity sensors on each knife valve to indicate to the operators whether the valve was open or closed.