Ammonium Nitrate Solution Process Overview

Ammonium Nitrate Solution Process

• Ammonium Nitrate solution (ANS) is produced at a strength of 90-94% m/m.
• ANS is pumped from either ANS 1 or ANS 2 to Tank 5 for strength reduction.
• The target strength in Tank 5 is 87.5%.
• Strength adjustment is achieved by dosing weak ammonium nitrate solution into Tank 5.
• Dosing control valve X1 opens and closes based on feedback from a density meter in Tank 5 (DT-XXX), ensuring the desired concentration.
• A timer mechanism limits the dosing duration to prevent overdosing and allow for proper mixing.
• A jet mixer and circulation line within Tank 5 ensure efficient agitation of the solution.

Control Instruments

• Density Meter (AE XXX): Measures the strength of the ammonium nitrate solution in Tank 5.
  • Fails in a fail-low mode, meaning it indicates a lower value than the actual if it fails.
• Dosing Control Valve (X1): Controls the flow of weak ammonium nitrate solution into Tank 5.
  • It operates in both manual and automatic modes.
  • It has a fail-closed functionality, meaning it stops the flow of weak ANS if it fails.
  • It is interlocked with Tank 5 high level and absence of a pump in operation.

Control Philosophy

• Target Concentration: 87.5%
• Control Method: Dosing of weak Ammonium Nitrate Solution (30-50%)
• Control Variable: Density & Temperature

Control Scenario Planning

• Scenario: High concentration in Tank 5.
  • Response: Dosing valve X1 opens and dosses for a timed duration to mitigate high concentration. Operators then can export the solution to the Tank Farm after achieving uniform mixing.
  • Failure to Respond: Valve failure results in no dosing due to the fail-closed functionality, preventing concentration adjustment.

This quiz covers the process of producing Ammonium Nitrate Solution (ANS) and the control mechanisms involved in adjusting its strength. Key instruments like the density meter and dosing control valve are explored, highlighting their roles in ensuring the proper concentration in Tank 5. Test your understanding of these processes and their controls.