Cement News

New milestone in rotary kiln operation

Heidelberg Materials is continuing the modernisation of its plant in Slite on the Swedish island of Gotland. The plant is being designed to produce climate positive cement, using ambitious carbon capture and emission reduction technologies.

In another milestone, KIMA Process Control GmbH will supply the most energy-efficient and environmentally friendly kiln shell cooling system for the entire kiln length of 55 m: a KILNCOOLER ‘stationary’.

The concerns about using water to cool the furnace shell have been dispelled in recent years. Long-term studies by users of KIMA Process’ technology have shown that there are neither any changes in the molecular structure of the iron (hardening), or micro-cracks in the outermost layer of the furnace shell caused by evaporation. The system deployed at Slite will use 88 water jets (replacing powerful air blowers), which cool the furnace with centimetre-scale precision only where it is really necessary to protect the furnace steel and refractory material.

The switch from electrically driven fans, which consume up to 2 million kWh of electricity per year, to industrial water results not only in a reduction of up to 1700 t of CO2, but noise emissions are also drastically reduced, according to the VDZ (Association of German Cement Works). For the nearby residents of the plant in Slite, this will mean a significant improvement and HeidelbergMaterials will make major operational savings: the cost of the water required is just 2% of the previous electrical cost.

In addition, pinpoint cooling also brings significant advantages in process engineering. By means of IR pyrometers, the furnace shell is precisely measured to within 10 cm2 and a current target temperature is specified every half meter. This temperature, which depends on the degree of refractory wear, is now secured around the entire kiln circumference by means of a water spray.

A highly uniform buildup in the kiln protects the refractory material and ensures much quieter kiln operation. Heat energy supplied by the main burner is not lost through unnecessary cooling of the kiln shell. This also means less fuel use. Deformations of the kiln shell can be reduced, if not prevented, at an early stage.

The investment in the KILNCOOLER ‘stationary’ system, will bring the cement plant in Slite an economic benefit in the shortest possible time, but for the cement industry this project represents a new milestone in terms of BAT – Best Available Technology – in the operation of rotary kilns.

Read the article online at: https://www.worldcement.com/product-news/17112022/new-milestone-in-rotary-kiln-operation/

Source link

Leave a Comment