Regenerative thermal oxidizing towers (RTOs) depend on the ceramic media within to optimize the tower’s performance and efficiency. The selection of ceramic media type can make a significant difference throughout the lifespan of the RTO in terms of time and costs. There are differences and nuances among ceramic media choices. Understanding these differences can help operators and plant managers make a well-informed decision that helps reach target goals for pollutant removal and air quality control while cutting maintenance time and sparing energy expenditures.

FLEXERAMIC® structured packing and random packing are commonly used in RTOs (Regenerative Thermal Oxidizers). The use of packing facilitates the transfer of heat between the exhaust gases and the incoming air streams. A vital component of any RTO is using proper heat transfer media to mitigate potential problems while ensuring reliable, economical and safe operation.

Structured Packing example for RTOs

Comparing the differences between FLEXERAMIC structured packing and ceramic random packing

In planning a rebuild or an original design, engineers can use a mix of random ceramic saddles and structured packing, all random packing or all structured packing. Keep in mind there are critical differences between these two packing materials that make FLEXERAMIC structured packing available from Knight Material Technologies a more attractive option.

Here are some benefits of using FLEXERAMIC structured packing over random packing in an RTO:

The difference between structured packing and random packing comes down to the increased surface area that provides efficiency in pressure drop, heat transfer and resistance to fouling.

Structured packing vs. random packing data

Let’s look at the data differences between FLEXERAMIC structured packing and random packing as tested by an independent lab. The test conditions were based on two 8′ deep beds with 70°F inlet, 1500°F combustion, and 180-second switch time. The fuel is natural gas with 0% excess combustion air added.

Thermal Energy Recovery Efficiency*
150 SCFM/FT2 200 SCFM/FT2 250 SCFM/FT2 300 SCFM/FT2 350 SCFM/FT2
FLEXERAMIC® 28 Structured Packing 95.54% 95.12% 94.77% 94.46% 94.19%
Ceramic Random Media ~93.5% ~92.8% ~92.3% ~91.9% ~91.5%

*Recommended efficiency is 95% and above

Pressure Drop (inches wc through inlet and outlet beds)
150 SCFM/FT2 200 SCFM/FT2 250 SCFM/FT2 300 SCFM/FT2 350 SCFM/FT2
FLEXERAMIC® 28 Structured Packing 3.8″ 6.8″ 10.6″ 15.3″ 20.9″
Ceramic Random Media ~5.3″ ~9.45″ ~13″ ~21.35″ ~29.15″

Cost-benefit of structured packing vs. random packing

Overall, structured packing is better than random packing at meeting trends for RTOs to move to efficiency, energy consumption and regulation compliance since the design that begins with structured media will meet the operational objectives and provide more prolonged operational use. All of these differences should be considered when designing or rebuilding an RTO.

Start your engineering consultation with a sales engineer

Do you want to talk about the latest RTO packing material technology for a refurbishment or new installation? The engineering staff at Knight Material Technologies can support your next project from conception through completion and help design the packing for your application. Improve your RTO performance with a call to Knight today. For more information on FLEXERAMIC structured packing, see the brochure.

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