Calcia boosts clinker burning process with kiln inlet system

The main tasks of process gas analyzers at the kiln inlet in cement plants are as follows:

• Measuring the composition of the process gas in the rotating part of the kiln

• Controlling the excess air (O₂) ratio at the kiln furnace inlet

• Controlling carbon monoxide (CO) concentration and combustion quality

• Monitoring NO and NO₂ concentrations for emissions and temperature control

• Monitoring volatile sulfur compounds (SO₂)

• Transmitting information on the concentrations of the above-mentioned gases for burner control, fuel and raw material mixture adjustment and process gas control.

In addition to these features, other customers have benefited from the analysis system's ability to provide insight into the internal chlorine cycle by measuring the concentration of hydrogen chloride (HCl) in the kiln, helping plant operators reduce blockage issues caused by high chlorine volatility. Furthermore, this information is useful for limiting the volume flow of chlor bypass gas and thus keeping HCl emissions low.

Taking measurements in harsh environments with dust concentrations of up to 2,000 grams per cubic meter (g/m3) and temperatures approaching 1,400°C is a challenge, but the SCP3000 high-temperature gas sampling probe, with its water-cooled probe and highly effective self-cleaning function, is a reliable solution for gas sampling at the kiln inlet. Thanks to its special design and high-pressure backpurge system, probe clogging is prevented, even when used in kiln gases with high dust content and containing large amounts of chlorine and sulfur compounds. The optimized and reinforced gas inlet at probe is mounted at an angle opposite to the gas flow, minimizing the direct entry of dust and particles into the sampling system. This protects the highly corrosion-resistant probe tube, available in lengths from 2.5 to 4 meters, from abrasion and clogging.

Endress+Hauser is one of the few suppliers to offer complete gas extraction probe and analyzer solutions. In addition, it has the longest experience with gas analyzers at the inlet of cement kilns, based on Hot-wet measurement technology.  With the MCS300P HW multi-component gas analyzer and its non-dispersive infrared (IR) photometer, cement manufacturers can measure up to 6 active gas components in the IR range, plus oxygen. For kiln inlet applications, the analysis system is normally configured to measure all combustion-related gas components such as O₂, CO, CH₄ (if natural gas is used), NO, CO₂, and process parameters such as SO₂, HCI, and NH₃. Thanks to hot-wet measurement technology, the gas path is fully heated from sample probe to gas analyzer. This means that the extracted gases are always above the dew point, reducing the risks associated with condensates, such as acid corrosion or pipe blockages. Since the gas sample is not cooled, even water-soluble components such as NH₃, HCl, and SO₂ can be measured with a single cell and without any gas treatment or calculation effort. In addition, SICK's hot-wet technology does not require additional gas coolers, special acid filters, water traps, or hydrogen peroxide dosing systems to remove corrosive SO₂ from the process gas. This reduces maintenance efforts and consumables.

The combination of the SCP3000 high-temperature gas sampling probe and the MCS300P multi-component hot-wet gas analyzer makes it possible to meet the challenges of measuring gases at the kiln inlet in cement plants, regardless of high gas temperatures, high dust loads, or corrosive gases, without the need for complex and maintenance-intensive sample conditioning systems. The automated self-cleaning and self-adjusting capabilities of the analysis system ensure high availability and result in significantly lower operating costs than conventional systems based on cold-dry measurement technology, which where the gas sample preparation tend to be very complex and difficult to maintain. As a result, the operating costs of hot-wet measurement technology can be up to 40% lower than those of systems based on cold-dry measurement technology. The system is optimized for use with difficult fuels with high sulfur content (e.g., petroleum coke) and alternative fuels (tires, RDF, oils, wood chips, medical waste, etc.), making it reliable even when used in highly aggressive measurement atmospheres.

©Endress+Hauser

©Endress+Hauser

In the future, Calcia plans to implement Endress+Hauser’s Condition Monitoring solution, a new digital service that increases the availability of the process gas analysis system at the kiln inlet. Monitoring Box is a digital solution for continuous monitoring of status of devices and plants, as well as the application itself. Vital data from connected devices is collected by the gateway, encrypted, and sent via mobile network, LAN, or Wi-Fi to a secure cloud host for further processing.

Condition-based maintenance monitors all vital parameters that indicate the health of the entire system – including the gas analyzer, the sampling system, and all auxiliary equipment such as the water-cooled gas extraction probe tube cooling system or the programmable logic controller.

This collected data can be viewed and evaluated in the Condition Monitoring web application. Significant changes in the condition of the device are monitored, enabling maintenance personnel to intervene in time and ensure system availability. In this way, the Condition Monitoring service improves equipment availability and reliability and helps prevent unplanned breakdowns and downtime. Optionally, connected devices can also be monitored by Endress+Hauser as part of a service contract.

This information makes it possible to identify problems before they occur. For operators, this translates into a longer system life cycle and a faster return on investment. In addition, this solution enables Endress+Hauser to optimize maintenance and ensure immediate troubleshooting, reducing travel costs and working hours for maintenance technicians.

These savings are directly passed on to the cement manufacturer. Thorough remote checks also improve the quality of data from analysis systems. These improvements increase overall maintenance efficiency and can extend the life cycle of machines.

Thanks to the good relationship between SICK and Calcia, as well as many other members of the Heidelberg Materials Group worldwide, the Couvrot plant has been equipped with the  SCPS3300 process gas analysis system at the kiln inlet, consisting of an SCP3000 gas extraction probe and an MCS300P hot-wet extractive multicomponent gas analyzer, the most suitable solution for this essential and demanding measurement application. The Beaucaire and Airvault sites also installed this solution.