Morgan Technical Ceramics, Southampton, UK, has reportedly seen significant improvements in the operation of four of its sinter fire kilns following a rebuild

Top hat kiln

using a complete engineering solution supplied by sister company Morgan Thermal Ceramics. The rebuild project has resulted in dramatically reduced energy costs for each of the four kilns, while delivering assured production efficiency, durability and increasing the total
lifespan of the kilns.

Due to the processing of high volumes of lead zirconium titanate (PZT) ceramic—a piezoelectric material used in ultrasonic sensors and transducers that are sintered in the four kilns—the brick linings in the kilns previously needed to be replaced every 12 to 18 months. The sintering temperatures of up to 1290°C and the high lead content of the products was causing parts of the kilns’ roof and walls to quickly corrode. This increased the time taken for the kilns to reach their operating temperature and resulted in a significant reduction in productivity and an increase in energy usage.

“Typically, the heat within these kilns increases by 100°C every hour,” said Tony Beswick, general manager of the Southampton site. “The impact of corrosion within the roof and walls means the kiln struggles to reach the required temperature during the desired timeframe. For example, on average it should take 12 hours for a kiln to heat to 1200°C, but we were experiencing delays of up to 10 hours.

“The lead-rich atmosphere was also damaging the brick face within the kiln, causing ‘puddling’ in the roof—drips caused by lead attack. In severe cases, these would drip over the saggars (alumina-based content firing trays) housed in the kiln, causing them to stick to each other and to the sides of the kiln. This exposes the system to an increased risk of damage when lifting the saggars from the kiln, potentially causing the items inside to break.”

Multi-Faceted Solution

Morgan Thermal Ceramics proposed an integrated engineered solution based on a range of products to enhance the efficiency of the kilns. One of the Superwool® Plus fiber products, Superwool Plus Blok, was specified for the cold face insulation of the units, with the company’s Tri-Mor® insulating castable and the JMTM 30 insulating firebrick (IFB) proposed for the hot face insulation.

Superwool Plus insulating fiber is a high-temperature insulating wool that achieves increased energy savings by maximizing the number of fibers available in the insulation layer. In addition, it offers low bio-persistence, which provides a key health and safety benefit during installation and removal.

The roofs of the kilns are now constructed from Tri-Mor Morflo, a low castable cement incorporating fine fillers and dispersants that can significantly reduce water demand, while the rest of the kilns’ hot face lining continues to use Morgan Thermal Ceramics’ JM™ 30 IFB, 76 mm in depth and capable of withstanding temperatures up to 1650°C. The structural integrity of the company’s JM IFB range makes them capable of tolerating erosive and abrasive environments.

“While we used to see ‘puddling’ in our previous systems after only a few weeks, the new insulation system has ensured that the kilns have been operating efficiently for eight months now,” Beswick said. “To date, the maximum time to bring the kilns up to temperature has been no more than two hours, resulting in lower energy costs, increased production and reduced total cost of ownership.

“Using Tri-Mor Morflo castable and the JM 30 IFB for the hot face lining, backed up by Superwool Plus Blok, means we can rely on the systems to provide a consistently high level of output. The products have delivered a superior all-round performance to our operations in Southampton and we are delighted with the results.”

For more information, visit www.morganthermalceramics.com.