Next-generation probe helps cement industry increase safety and sustainability in kilns
AS governments focus on reducing emissions, cement plant owners are seeking alternative fuels and raw materials (AFR), new processes and additives as a means of reducing their environmental impact. This approach brings new industry challenges. The increased use of AFR can lead to dangerous pockets of incomplete combustion within a kiln and an increase of vaporized volatile gases, leading to an increased risk of explosion and costly kiln stoppage.
ABB have developed ProKiln, a gas sampling system, to meet these challenges, offering permanent and uninterrupted process control in rotary cement kilns. The new cement kiln inlet gas system features powerful probe cleaning with increased mechanical strength, which includes a dual probe retraction system unique to the market to ensure no sampling interruption.
One of the main issues facing kiln operators when gathering data is the scaling of material both on the probe’s surface and in the sample intake area, as well as material falling in through the riser duct. The ProKiln overcomes this problem with an extractive filter in the tip of the probe which separates sample gas from the dust load. In addition, the ProKiln’s patented technology uses two air blasters to clean the tip of the probe, maintaining a sample path for critical analysis even under extreme conditions.
A 3D printed stainless steel nozzle ensures that no blockages occur at the tip of the probe and the system is mounted on a buggy running on a retractor which carries the probe safely in and out of the kiln, allowing it to be cleaned automatically. Measuring 3m in length, the gas probe is water cooled with an extractive filter placed at the sample and flow is maintained by the blasters. A cooling system provides recirculating water for temperature control, essential in operating conditions where process gases can reach 1,200°C.
ProKiln has been put through its paces during a trial with Holcim, the world’s largest cement producers. The test ran for six months at the company’s Lägerdorf plant, which uses more than 80% alternative fuels. The reduced maintenance effort and increased availability convinced the customer to replace the current installation with ProKiln.