Exfoliation Monitor for Natural Gas Pipelines
After several years of operation, scale, deposits, and corrosion products build up on the ID surfaces of natural gas pipelines.  When these solids exfoliate or during on-line mechanical cleaning of the pipeline, they are transported downstream to the end user's system where they accumulate in low flow areas of the system and plug and erode burners, valves, elbows, etc.  
Monitoring of the flow of particles in the gas pipeline allows gas suppliers and end users to be alerted when there is a significant increase in concentration and to estimate the loading on particle removal systems (filters, etc.).  In addition, the ability to monitor the oxide concentration during on-line mechanical cleaning allows better control and evaluation of cleaning effectiveness.
Description of the Monitor
The Exfoliation Monitor is a continuous in-line instrument for monitoring of solid particle flow in natural gas pipelines.  It quantitatively monitors the impact of solid particles on a metal Detecting Probe.  It measures the number of particles per second and the mass flow rate, and provides a histogram of particle size distribution.  The Monitor is a multi-channel acoustic emission instrument capable of detecting individual particle weights above 10-11 grams (5 micron for iron oxides depending on the flow velocity).  Up to eight locations can be monitored by one instrument using multiple Detecting Probes.  The Detecting Probe is permanently inserted into the monitored pipe (Figure 1).  It can be in a fixed position or traversing.
The instrument has been used in many applications including:  monitoring of exfoliated oxides to prevent solid particle erosion in steam systems (1-3), cleaning of pipes (4), and water droplets in natural gas (5).  
Additional information can be found at: www.steamcycle.com/particle.htm and www.steamcycle.com/particulate_probe.htm
Options
On-line Insertion Mechanism for inserting and removing the Detecting Probe during operation of the pipeline (Fig. 1)
Traversing Detecting Probe for monitoring across the inside diameter of the pipe
Sample withdrawal probe

Figure 1.  Exfoliated Oxide Monitor Detecting Probe with On-line Insertion Mechanism

References
1.
O. Jonas and R. Freeman. Measurement of Exfoliated Oxides in Morgantown Potomac Electric Power Company.  Jonas, Inc. Report, August 1986.
2.
O. Jonas and H. Clements. Monitoring of Exfoliated Oxides in Morgantown 2 after Chemical Cleaning of Superheater and Reheater. Jonas, Inc. Report, Sept. 1988.
3.
O. Jonas. "New Continuous In-Line Method for Monitoring of Solid Particles and Results of Field Testing,” Presented at ASME-EPRI Conference on Solid Particle Erosion of Utility Steam Turbines, New Orleans, LA, March 7-9, 1989.
4.
O. Jonas. “Monitoring of Superheater and Reheater Exfoliation and Steam Blow”, 56th International Water Conference, Pittsburgh, October 1995.
5.
O. Jonas and L. Machemer. "Particulate Probe Answers Water Content Questions for Alabama Gas Pipeline." Oil and Gas Journal. September 18, 2000.