Gamma Scanning Columns with Trays

TowerScan's gamma scanning service increases your profitability and provides a fast, efficient means of determining:

• the location of damaged and/or missing trays

• the severity and extent of flooding, entrainment, foaming, or weeping

• the location of process bottlenecks

• the depth and relative densities of the aerated liquid on the trays, and the liquid level in the base of the column

• and preventing unnecessary shutdowns

Column scans, a well established troubleshooting tool, are quick, safe, and easy to set up. They require no support from process personnel other than drawings of the column, a work permit, and access to the top of the column.

A gamma scan is performed by placing a small radioactive source, and a sensitive radiation detector on opposite sides of an operating distillation column. As seen in Figure 1, the source and detector are aligned so that the path between them is across the tray active area, but avoids intersecting the tray downcomers. Maintaining a constant geometry, any variation in the signal is due to density differences within the column, as the scan proceeds down the tower.

In Figure 2, overlying a baseline scan (red), is a scan profile (blue) of a column that had experienced damage to tray 6, the debris from which has caused flooding from tray 9 upwards. The second scan (green), on the lower half of the chart, shows the profile typically seen when a column experiences entrainment problems.

The effectiveness of gamma scanning is always increased when the opportunity arises to compare two or more scans, whether they be at different operating conditions, or a current scan vs. a baseline scan taken after a turnaround. These situations offer great process optimization opportunities.

Unsurpassed data quality is just one of the results of TowerScan's equipment standardization program and calibration routines. A higher data resolution means greater accuracy. Our commitment to quality far exceeds that of any other company.

Our engineering staff have been working in the gamma scanning industry since 1989, and have performed hundreds of scan across the U.S., Canada and around the world. Already the leader in quality and cost effectiveness, our customers will continue to make a "TowerScan" their first choice for column troubleshooting and process optimization. Call TowerScan today to find out how we can help you succeed.

TowerScan, P.O. Box 347, Corunna, ON N0N 1G0. Tel: 810-984-3116; Fax: 810-984-3119.