Stationary Time Monitoring Study

Stationary Time Monitoring Study provides continuous, real-time evaluation of column performance using multiple detectors placed at specific elevations. This non-intrusive technique monitors density changes, foaming rates, flooding points, and hydraulic behaviour over a defined period. By analysing these variations, plant engineers can fine-tune tower operations, optimise process parameters, and prevent potential upsets — all while the unit remains in service.

Overview

Advanced multiple-detector gamma-ray monitoring at fixed elevations to track density changes, foaming and flood points in fractionator columns, tray towers, packed beds and process piping  while your unit stays on stream.


Continuously observe column hydraulics over time and gain real-time visibility of flood onset, maldistribution and internal integrity to support predictive maintenance and process optimisation.

Supporting refinery, petrochemical and gas processing plants with on-line gamma-ray diagnostics.

What is Stationary Time Gamma-Ray Monitoring?

Stationary Time Monitoring is a specialised gamma-ray scanning method where the source and detectors remain fixed at one elevation while density changes are recorded over time. A collimated gamma-ray source is placed on one side of the vessel and a vertical array of detectors on the opposite side, each measuring transmitted radiation at one-second intervals for several minutes.

The technique is ideal for:

  • Tray towers and packed bed towers;
  • Large refinery fractionator columns;
  • Critical process lines and transfer piping.

By monitoring under different operating conditions, operators see how the column responds to load changes, feed swings and start-up/shutdown transitions.

How the Technique Works

Simultaneous multi-detector measurement

A collimated gamma source and multiple detectors are aligned across the vessel. Each detector corresponds to a specific scanline or radial position, and radiation intensity is recorded every second over a defined period (typically 5 – 7 minutes).

Density behaviour over time

Stable hydraulics produce flat, consistent detector profiles. Changes in foam height, liquid level and vapour liquid mixing appear as clear trends and fluctuations in the detector count curves, allowing early identification of flooding or maldistribution.

Non-intrusive and standards-compliant

No insulation removal, tray lifting or vessel opening is required. The study is performed under normal operating conditions and can be executed in alignment with ISO 23159 Gamma Ray Scanning Method on Process Columns and applicable radiation regulations.

Key Applications of Stationary Time Monitoring

For towers and columnsFor process optimisation
  • Monitoring fractionator columns at draw trays and baffle zones.
  • Assessing tray loading, froth height and vapour liquid interaction.
  • Confirming packing performance and liquid distribution.
  • Evaluating flood approach and relief capacity during rate changes.
  • Establishing baseline density profiles for long-term hydraulic trending.
  • Early detection of foaming before trips or off-spec product.
  • Pinpointing flood points and safe operating envelopes.
  • Identifying channeling, maldistribution or tray damage.
  • Validating the impact of revamps, cleaning or tray replacement.
  • Supporting predictive maintenance programmes for critical towers.

Benefits for Your Operation

Operational & hydraulic insight Business & reliability gains
  • Time-based monitoring rather than a single-point snapshot. Direct evaluation of density changes at critical elevations.
  • Determination of foaming rates and flood onset.
  • Correlation with pressure, temperature and flow data.
  • Clear basis for adjusting column operating windows and control strategies.
  • Fully non-intrusive zero production loss during monitoring.
  • Lower risk of unplanned trips and product quality issues.
  • Better prioritisation of inspection and maintenance resources.
  • Establishment of hydraulic baselines for long-term performance tracking.
  • Enhanced confidence in operating closer to equipment limits.

Benefits for Your Operation

  • Operating close to flood or capacity limits and needing to verify margin.
  • Recurring foaming, high differential pressure or level instability.
  • Suspected tray damage, fouling or maldistribution based on other indicators.
  • Quantifying improvement after revamps, cleaning or tray replacement.
  • Implementing 6 – 12 month reliability or performance monitoring cycles.

What You Receive

  • Monitoring plan and detector layout for each elevation.
  • Time intensity curves for all detectors and scanlines.
  • Interpretation of density behaviour (foaming, flooding, channeling, stability).
  • Comparison against baseline or previous data where available;
  • Actionable recommendations on:
    1. Operating window optimisation.
    2. Inspection and turnaround focus.
    3. Need for further monitoring or complementary scans.

Why Work with Scansolution

  • Specialists in gamma-ray diagnostics for columns, towers and piping;
  • Proprietary SCANSOLUTION® Stationary Time Monitoring system with multiple detectors;
  • Experienced refinery and petrochemical field teams;
  • Methods aligned with ISO 23159 and national radiation requirements;
  • Ability to combine stationary monitoring with:
    1. Vertical gamma column scans;
    2. Tomographic imaging and other process diagnostics.

Scansolution turns complex tower hydraulics into clear, actionable information. Our Stationary Time Monitoring Study provides the visibility needed to operate safely and efficiently, validate revamps and support long-term reliability strategies.

Stationary gamma-ray monitoring Fractionator diagnostics
Hydraulic performance mapping Predictive maintenance support

What is Stationary Time Gamma-Ray Monitoring?

Frequently Asked Questions

Does Stationary Time Monitoring replace a full column scan?

No. A vertical gamma scan gives a full-height density profile at one point in time. Stationary Time Monitoring tracks density changes over time at one elevation. Combined, they provide a much deeper understanding of column hydraulics and mechanical condition.

Each elevation is typically monitored for 5-7 minutes at one-second intervals. Multiple scanlines can be acquired in a single shift without impacting unit operation.

Yes. Scansolution conducts all work under strict radiation safety procedures and national licensing requirements, using controlled, collimated sources and trained personnel to minimise exposure to plant staff.

Many operators repeat Stationary Time Monitoring on critical towers every 6—12 months to build trends, validate the impact of maintenance and support reliability-centred maintenance planning.

Plan Your Next Stationary Time Monitoring Campaign

If you operate critical fractionators, absorbers or packed towers and want deeper visibility into their hydraulic behaviour, Scansolution can design a Stationary Time Monitoring programme tailored to your process, turnaround schedule and performance objectives.