The Flow Scope Hi-T, ASE’s high temperature inspection camera, offers “eyes inside” industrial equipment and duct systems. The Flow Scope Hi-T not only allows visibility of hard to reach places, it can also endure extreme temperatures. The benefit is that it can be utilized even while equipment is under operation, for real-time representation of industrial processes. Today’s blog highlights how our high temperature online video inspection camera was put to use in a power plant for improved pollution control.
A Problem with Coal Ash Pluggage
Selective Catalytic Reduction (SCR) is a technology employed by many power plants to reduce pollution from the combustion process. In SCR equipment, hot flue gases are routed through layers of a catalyst to convert harmful nitrous oxides (NOx) to harmless nitrogen gas (N2). At coal-fired power plants, one common hindrance to SCR effectiveness occurs when large particle ash (LPA) and finer ash material plug and restrict flow through the catalyst layers.
One US-based power plant was having an issue with the performance of their SCR equipment. It was suspected that LPA pluggage could be affecting pressure loss and the efficiency of the system. An LPA screen was in place at the reactor inlet as a preventive measure. The screen is meant to prevent LPA from entering the reactor and plugging the catalyst.
High Heat Video Inspection
The Flow Scope Hi-T captured live video footage at two critical locations in the flow stream. The first was at the LPA screen at the entrance to the SCR. The second location was at the face of the first catalyst layer, which was experiencing significant ash buildup.
High temperature video inspection occurred at two locations inside the reactor
Prior inspections had been undertaken only during plant outages, with no airflow through the equipment, and all had shown minimal pluggage of the LPA screen. In contrast, the online video inspection was able to provide a representation of actual conditions at various operating loads. Since temperatures inside the SCR reach 700 F/400 C, a heat-resistant camera was needed.
The online video inspection resulted in some crucial findings. At the LPA screen, video footage (below) showed that the LPA screen was significantly more blocked during operation than when the screen was observed offline. The flow of the gas stream was pinning large particles up to the screen, causing higher velocities which can lead to premature screen erosion. The videos also showed that the catalyst was more susceptible to ash buildup at lower operating loads.
During a video inspection, the live video feed of the Flow Scope Hi-T is viewable on the included display module. All high-resolution videos are recorded and can be downloaded via a USB connection for reviewing. Observations from video inspections can be compared to measured process data, testing data, and CFD modeling results for a more complete picture of process health.
In this case, the video inspection was able to pinpoint problem areas and allow for targeted remediation efforts. Ultimately, the plant installed baffles to divert particles away from the screen and flow controls near the catalyst to prevent low velocity zones and excess buildup in those areas.
Add a High Temperature Inspection Camera to Your Toolbox
When industrial processes are suffering, plant operators shouldn’t risk blind fixes. The next time you need high-definition at high temperature, reach for the Flow Scope Hi-T inspection camera. Contact our team for a quote.