Claudius Peters Projects GmbH

Use of the CP g-cooler in waste heat recovery systems

CP/ Buxtehude

1 Extraction of the clinker heat
a) conventional
b) by means of a g-cooler

CP/ Buxtehude

2 Design of a g-cooler, schematic

CP/ Buxtehude

3 Stagnant clinker zones and voids at a round heat-transfer pipe

CP/ Buxtehude

4 Heat-transfer resistances bulk material - pipe - heat transfer medium

CP/ Buxtehude

5 Heat transfer coefficients along the height of the g-cooler

CP/ Buxtehude

6 Control volume around the i^th pipe level

CP/ Buxtehude

7 Comparison of the heat transfer area of air cooling and heat transfer oil cooling, reference operating case, variable heat-transfer-oil outlet temperature

CP/ Buxtehude

8 Reference operating case with lens-shaped pipes, heat-transfer-oil outlet temperature: 320°C

CP/ Buxtehude

9 Comparison of lens-shaped pipes and round pipes, reference operating case, heat-transfer-oil outlet temperature: 320°C

CP/ Buxtehude

10 Arrangement of round pipes in the cooling pipe bundle

CP/ Buxtehude

This article discusses the possibility of improving the utilization of waste heat from a clinker cooler for power generation by use of a g-cooler with upstream recuperator. The g-cooler is a moving bed reactor with indirect heat dissipation. Up to now, this cooler has always been operated with cooling air. With a view to achieving more efficient heat extraction, an analysis was carried out to assess the suitability of a g-cooler utilizing heat transfer oil as the coolant and evaluate the consequences.

1 Introduction

The Claudius Peters g-cooler is a moving bed reactor for indirect cooling of free-flowing bulk materials. The thermal content of the bulk material is transferred to a coolant flowing through a pipe bundle with specially shaped and arranged pipes. Originally, the g-cooler has been developed for cooling cement clinker down from t_K,in ~= 400°C to t_K,out ≤ 100°C using air as the cooling medium. For this purpose, a short grate cooler/recuperator is installed downstream of the rotary kiln, to cool the clinker down from the kiln outlet temperature of t_K,kiln ~= 1350°C to approx. t_K,in,...