Minerals ProcessingPyro Process
The performance of the preheater and calciner are governing factors influencing the heat consumption of modern kilns. The Low Under-Pressure Cyclone (LUCY) preheater assures the desired heat exchange while keeping pressure drop low.
Key components of the preheater have been developed and refined to achieve the best performance parameters. IKN provides preheater concepts to match customer specific requirements.
The main features of the LUCY Preheater are:
- Optimum meal dispersion into the gas stream by splash boxes.
- Excellent heat exchange between raw material and gas.
- Efficient separation of raw meal at each cyclone stage with low pressure drop.
Basic parts of the preheater are cyclones with low pressure loss. Additionally, the LUCY Preheater’s top stage cyclones are designed for maximum dedusting efficiency.
The number of cyclone stages determines the specific fuel consumption. It is a compromise between the efficiency of the preheater and drying requirements of the raw meal.
The introduction of calciner technology increases clinker production and ensures that the rotary kiln keeps a manageable dimension.
Calcination rates in excess of 90% are achieved with approximately 60% of the total fuel directed to the calciner. As combustion and calcination of raw material take place outside of the rotary kiln, the heat loading of the kiln is reduced and smaller rotary kilns are possible.
All IKN calciners are based on a modular system. Systems can be designed according to the fuel used or other specific requirements.
ICC – Internal Combustion Chamber
The ICC is a state of the art inline calciner and makes your system ready for the future.
The development of the ICC was based on the KKN calciner, which is in operation in many plants. The installation is recommended if it is intended to burn up to 60% of fuel in the calciner.
The ability to burn alternative fuels can be improved by creating a high temperature zone at the bottom of the ICC. Hence, a higher percentage of alternative fuels is possible. Various meal and tertiary air inlets ensure maximal flexibility.
SCC – Separate Combustion Chamber
The increasing use of alternative fuel is of primary interest in the cement industry. The SCC offers an excellent solution for preheater upgrades.
With a separate combustion chamber (SCC), alternative fuel rates up to 100% are achieved. More alternative fuels, such as ground plastic, cloth, paper or wood may be used.
The high-temperature core of the SCC simplifies the combustion of alternative fuels that are difficult to burn or ignite, without increasing the emission of harmful substances. The core is maintained by a supply of hot combustion air from the TAD.
NOx reduction potential in the calciner is strongly influenced by the fuels used. Staged combustion is an additional measure for NOx reduction.
Tertiary air is directed to the upstream part of the calcining channel below the swirl head, allowing staged combustion to take place. The maximum efficiency is achieved when an area with under stoichiometric combustion conditions is created in the lower calciner part.
Double G Damper
Most calciner installations require tertiary air taken from the kiln hood or cooler housing. IKN’s Double G Damper model is specially designed for both, air flow regulation and complete shut off in tertiary air ducts.
Two independent guillotine type gates fulfill the two main process functions of the damper:
The regulation gate is active during normal kiln operation. It is manufactured from heat resistant steel pipes, covered by precast abrasion resistant refractory blocks.
Located behind the regulation gate is the heat resistant shut off gate. Both gates in conjunction are used to close off the tertiary air duct during start-up and shut-down cycles.