Improvements in Extruder Pump
Revamping of redundant Quantum PLC
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The client needed to place a safety brake system in the gantry crane, located in the pool area for hazardous materials. The reason for this request is based on the safe handling of such materials.

The system should act under some of the following conditions:

  • Overspeed of the drum
  • Overweight
  • Drum movement without command (sliding)
  • Absence of drum movement with command
  • Emergency stop
In additional to the above, the client raised the possible presence of a lifting mast which could interfere with the movement of the crane. Therefore, the system was required to be able to avoid collisions in case of being out of position.

Implemented Solution

It was proposed to place the Caliper brake system, which is controlled by a Siemens fail-safe CPU 3RK3 Advanced

The problem was faced as follows:

  • Drum movement without command (sliding) and absence of movement with command
    A Siemens S7-1214 CPU was placed, detecting the faults and sending them to the fail-safe CPU
  • Overweight
    To solve overweight problems, a dry contact of the existing balance was used, which is activated when the weight to be lifted exceeds the defined limit.
  • Overspeed of the drum:
    A safe speed monitor Siemens model 3TK was installed. Its speed limit was set up in conjunction with the client. The drum speed is calculated by Heidenhain encoders, attached to the main drum and the auxiliary drum.
  • Possible presence of a lifting mast:
    Omron photoelectric sensors were settled on the gantry for early detection of interference with such mast, and by sending a signal to the 3RK3 CPU Advanced, the bridge is stopped to avoid the collision.

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