Seeing the invisible
Keyur Shah, SB Engineers, and Alexandra Graf, PROMECON, discuss how real-time flow data can unlock energy efficiency in the clinker cooler.
The clinker cooler is central to a cement plant’s energy efficiency. Beyond lowering clinker temperatures from around 1400 °C to below 100 °C, it enables heat recovery through the air streams. Efficient coolers recirculate this heat as secondary and tertiary air to the kiln, reducing fuel demand and improving thermal balance. In modern plants with waste heat recovery systems (WHRS), the cooler’s exhaust air also contributes to electricity generation, often covering up to 30 % of the plant’s total power needs, enhancing competitiveness.
Getting the right Balance
Hans Conrads, Promecon, outlines how new gas measurement technologies could help enable a more consistent and accurate gas flow balance in the clinker cooler, leading to a more efficient and sustainable cement making process.
Over the past 15 years, a new measurement technology has entered the cementproducing world; this is the measurement of dusty process gas flows by cross correlation-based velocity calculation. This new technology has opened up the door for process optimisation in the pyro process, the raw milling section, as well as the finished product grinding.em utilises the triboelectric principle. Electrical signals created by (dust) particle clouds passing each of the upstream/downstream sensors are cross correlated and referenced by their time shift. The digital system requires no calibration, ...
In Full Flow
Hans Georg Conrads, PROMECON, outlines how gas flow can be better controlled and handled in the grinding and pyro processes in order to improve the efficiency of cement production.
In the cement industry, pressures as well as temperatures have often been used to calculate the process gas flows, however this method leaves uncertainty about the real flows of gas as well as enthalpy in the process.
Today, the following processes in the cement industry are of special interest when it comes to process gas flow measurement.
Nearly all these applications have several things in common which usually have a significant impact on conventional gas flow measurements.
Go with the Flow - efficient gas flow measurement in cement plants
Introduction
For the proper operation of equipment in a cement plant, knowing the flow rate is essential. In the past, high temperature and particulate in the gas stream have prevented online gas flow measurement. But the Promecon Air Flow System utilises the particulate to measure the velocity of the gas stream.
Measurement technology
The system utilises the triboelectric principle. Electrical signals created by (dust) particle clouds passing each of the upstream/downstream sensors are cross correlated and referenced by their time shift. The digital system requires no calibration, ...
Getting the right Balance
A new digital time-of-flight-based cross-correlation technique, employing pairs of robust infrared sensors, enables hot recirculation gas flow into lignite beater wheel mills to be accurately measured, with significant potential benefits for mill control.
Cross correlation technique The control state space in which a beater wheel mill is operated and which is defined mainly by the enthalpy flows in and out of the mill can change rather quickly if individual parameters such as the water content of the lignite is changing rapidly. In this instance the mill gas in- and output flows can undergo changes which are hard to control as the amount of heat into and out of the mill is not known.
Measuring gas flow in the downcomer of the preheater tower
Introduction
For the proper operation of equipment in a cement plant, knowing the flow rate is essential. In the past, high temperature and particulate in the gas stream have prevented online gas flow measurement. But the PROMECON Air Flow System utilizes the particulate to measure the velocity of the gas stream. Since the first installation at a cement plant in 2001, the system has been installed in more than 75 plants worldwide. The direct measurement of dust-carrying gas flows has opened new ways to monitor, control, and optimize the cement making process.
Measurement Technology
The system applies the triboelectric principle. Electrical signals created by the dust particle clouds passing each of the upstream/downstream sensors are cross correlated and referenced by their time shift. With the time of flight between the two sensors and a fixed distance (usually 350 mm), the actual particle velocity is known. For small particles, zero particle slip is assumed. The digital system requires no calibration, imparts no pressure drop, and does not drift over time.
A measurement point requires the installation of a pair of sensors aligned parallel to the longitudinal axis of the pipe. Using the cross sectional area of the pipe, as well as the pressure and temperature of the stream, the volume and mass flow can be calculated. Note that the only real measurement is time and that the measurement itself is not affected by temperature or pressure conditions of the stream.
Beater Wheel Mill control
Introduction
Presented by PROMECONs CEO Mr. Conrads at the ICCI Conference in Istanbul, the publication describes a novel method measuring hot recirculation gas into a beater wheel mill and gives an outlook on the application of this measurement for the better control of the mill operation.
Novel methos using an optical signal
Beater wheel mills in lignite power stations usually have a flue gas recirculation duct which allows the use of hot flue gas to dry the lignite during the grinding process. The beater wheel itself is grinding element as well as mill fan at the same time. The speed of the wheel determines not only the crushing process of the lignite but also influences the gas flow through the mill. One of the operational issues of lignite mills is the correct control of the beater wheel rotational speed for which besides the feeder information and the airflows through the mill the recirculation flue gas flow into the mill is a process variable.
McON Air zur Luftmengenmessung in der Müllverbrennungsanlage Bonn
Einleitung
Der Einsatz von PROMECONs innovativer Messtechnik McON Air in der Luftmengen-Regelung in einer Müllverbrennungsanlage führt zu Reduktionen der Temperaturspreizung oberhalb des Rostes um fast 50% und damit zu einer deutlich optimierte Prozessführung.
Erfolgreiche Innbetriebsetzung in der MVA Bonn
Die Müllverwertungsanlage der Stadtwerke Bonn GmbH (SWB-Verwertung) wurde 1992 mit zwei Linien als thermische Verwertungsanlage in Betrieb genommen. Seit 2000 wird die Anlage mit drei Linien und einem Jahresdurchsatz von ca. 250.000 Tonnen Brennstoff betrieben.
Mit der erfolgreichen Inbetriebsetzung der innovativen Luftmesstechnik McON Air der PROMECON GmbH, welche die individuelle Regelung der Rost-Primärluft der Linie 3 der MVA Bonn unterstützt, ist eine deutliche und wegweisende Innovation für die Feuerführung an einer Müllverbrennungsanlage ausgeführt worden.