Water and power consumption reduction by gas conditioning tower system modification in cement industry

Abstract

Abstract Gas conditioning tower (GCT) is a vital equipment in cement industries. The main principle in this equipment is evaporative cooling, i.e. reducing the temperature of the hot flue gas by evaporation of cooling water. Thus, the water consumption is large enough to be able to cool the hot gas from about 400 °C to 150 °C or less. In this case study, the water consumption reduction of a GCT is evaluated before and after modification. The modification of the GCT system includes the change in operating condition and tower mechanical construction which are installation of flow deflector in the inlet pipe, the addition of two perforated plates, the reduction of the nozzle sprayers and the addition of tower length. Meanwhile, the dust removal replacement from Electrostatic Precipitator (EP) to Bag Filter (BF) system allows higher outlet gas temperature of the GCT which could reduce the water and power consumption significantly. The modification effect of the GCT system is analyzed in terms of water demand and energy savings using 100 days real plant data from PT Indocement Tunggal Prakarsa, Indonesia (ITP). It is shown that the modification can reduce the total water consumption by about 20 % and the specific power consumption by about 0.5 kWh/ton of Raw Mill product. The general equation for cooling water demand calculation based on heat balance has been modified as well for better real data approach incorporating air spray flow into the equation.