160KW Process Heater Control Panels (Mexico)

Bj Control Panels was approached by Watlow Limited to produce 3 thyristor controlled process heater panels destined for Mexico. These were to be used in the production of High Density Polyetheylene (HDP) at a new petro-chemical plant in Mexico.

The total budget for the new plant was $2.7 billion - our contribution was a very small portion of that amount, but a very important one.

The process heaters were to be rated at 160KW utilising a supply of 480V @ 60Hz. Due to the size and nature of the total plant construction, a main Engineering Procurement and Construction(EPC) contractor was appointed - this was to be Technip who are a French based company with worldwide subsidiaries.

Being a large company the amount of documentation for the project was vast, and it took several weeks, sometimes months, to get any drawings or documents approved prior to panel manufacture

The panels had to be designed with a host of safety and protection features including:-

  • Earth leakage protection
  • Element over temparature protection
  • Mains supply under and over voltage protection
  • Control supply under and over voltage protection
  • Cooling fan failure protection
  • Loss of control signal detection
  • DCS shutdown interface

After the designs were approved and the panels manufactured, the completed units had to be tested and inspected by a third party Technip apporved inspector. Once completed, the panels had to be transported to Bristol University to be seismically tested to Mexican earthquake standards. This involved mounting each panel onto a large hydraulically controlled metal plate - which was then vibrated over 3 axes to simulate a typical Mexican earthquake. Continuous measurements were taked using several 3 axis accelerometers - the results were plotted on graphs. This was repeated around 10 times, the panels were then inspected for any damage prior to being deemed to have passed the tests.

The video below shows the seismic testing process at Bristol University:-
  160KW thyristor controlled heater panel.

  3 axis accelerometer seismic testing.