Use of acoustic temperature measurements in the cement manufacturing pyroprocess

Temperature measurements of various gas streams in cement plants are essential for efficient process control. Most critical temperatures, usually below 900°C are reliably obtained by the use of traditional contact type instruments such as thermocouples. Secondary air temperature, however, is extremely difficult to measure due to the extremely harsh conditions in this part of the process. The secondary air can become extremely dusty at times creating a fierce sandstorm in the cooler throat. Many operators attempt to measure the gas temperature in the clinker cooler throat directly in the gas stream. Even if these devices can be maintained, the temperature measurement represents the temperature at a single point in the entire cross section of the throat area. Knowledge of the average temperature of the secondary air would provide better process information regarding optimizing the airflow distribution in the recuperation section of the cooler. In order to quantify the operating efficiency of a clinker cooler the average temperature of the secondary air should be known. Most often heat balances are used to calculate the secondary air temperature. Performance guarantees are often verified by heat balance instead of relying on the temperature indicated by a thermocouple.

Author: G. Kychakoff

Section: Control of production

Keywords: gas temperature, acoustic pyrometry, equipment test