GTZ (German Technical Cooperation) has funded a programme by which cutting edge technology shall be deployed to optimize high energy consuming processes. The programme is a joint undertaking together with the bureau of energy efficiency of the government of India. GTZ chose PROMECON as project partner for instrumentation and application support due to the experience and track record for measurements of hot and dust laden airflows.
The MECONTROL Air system was used to measure gas flows in the cement making process namely Raw Mill and Coal Mill gas flow, TAD, Cooler Exhaust and Cement Mill gas flows. In total 12 measuring points have been equipped with the correlation based technology MECONTROL Air system. MECONTROL Air makes use of unique patterns of electrical noise generated by particles passing the receiver rods. By correlating these patterns the time of flight between the receiver rods can accurately be measured. Since the principle is base on time measurement it is accurate and absolutely drift free.
The Beawar plant has 2 kiln lines. The optimization was carried out on line 2 with a capacity of 4500 t/day which was commissioned in 1997 by KHD Wedag. It is fed by one Raw Mill and fires mainly Pet Coke as fuel. It has a 6 staged double string kiln preheater and a tertiary air duct (TAD)
The main potential for energy efficiency optimization lies in adjustment of the different air flows in the cement plant. The four main fans only have a capacity of almost 6000 kW which is a major share of the energy consumption of the whole plant.
For optimisation the air flows have to be well balanced by means: Gas flow through raw mill depending on load, mill gas recirculation, ratio of raw mill gas and gas conditioning tower gas. Coal mill airflows. Flows through kiln or via pyro-string and finally at the cement mill.
The accurate and drift free MECONTROL Air flowmeters supply reliable measurement data during the optimisation process which requires several weeks and for ongoing operation in the future.
As a result of this optimisation the energy consumption per produced tonne of cement can be reduced or the plant throughput can be increased with the same energy consumption and basically unchanged plant hardware.
These measurements open the door for substantial energy savings or a throughput increase. The investment for the instrumentation and optimization can be amortised within less than two years. Finally a big success for everybody.