In 2012, INTEC was commissioned to build an efficient energy center with heat recovery for a polyester yarn production line - as a double system - to generate process heat for two production lines. The fuel to be used was primarily Chinese hard coal and small quantities of production residues from plastics. Hard coal has a high calorific value on the one hand and a sulphur content of up to 5% on the other. This required special measures to prevent corrosion caused by falling below the dew point. INTEC planned, manufactured and supplied a firing system with heat recovery of hot exhaust gases from the combustion of Chinese hard coal, consisting of a fluidized bed combustion system with ash cooling in the side bed and a thermal oil system (waste heat boiler).

The combustion heat of the exhaust gases is transferred to the thermal oil system. The hot thermal oil is fed into flash tanks specially developed by INTEC, where there is a sudden drop in pressure. This causes part of the thermal oil to evaporate (flash evaporation) and generates steam, which separates from the liquid phase. While the liquid thermal oil is fed to the heat recovery system, the steam generated is used for heating. The spinning heads for polyester yarn production are heated by the heat transfer oil in the vapor phase.

A comparable system was supplied to the company LeaPeng.

SCOPE OF INTEC

•     Planning, delivery, installation supervision and commissioning of two plants
•     Fluidised bed incineration plant with ash cooling (heat exchanger system)
•     Thermal oil system (ETA waste heat boiler)
•     Flash tanks
•     Control and regulation components
•     Pump station