Energy Management

Parallel Pre-heater Fan for Increasing the Production

Background

The equipment in a Cement plant are all designed based on a certain load factor of the Kiln. Normally the pre-heaters, coolers and other major equipment are always designed with good margins. Many companies have made use of these margins and achieved higher levels of production with small modifications. In some of the plants all the equipment might have excess capacity and only the PH fan might be the bottle-neck for increasing production. In such cases the pre-heater fan is replaced or modified to increase the output of the plant. The increase in output also aids in reducing the power consumption.

Previous status

A million tonne dry process pre-calciner plant was operating at a capacity of about 3000 to 3100 TPD. The major equipment had additional margin for increasing the capacity by another 10 %, but the pre-heater fan was operating at its full capacity.

Energy saving project

An additional small pre-heater fan equal to about 15 % of the capacity of the existing fan was installed parallel to the existing PH fan. The head of the new fan was the same as that of the existing fan.

Implementation methodology & time frame

The new PH fan was installed parallel to the existing fan. The fan was installed during running of the plant. The new parallel fan was hooked up during a small stoppage of the plant.

Benefits of the project

There was an increase in the output of the Kiln, reduction in pressure drop of the pre-heater, reduction in Kiln section power consumption and reduction in Kiln specific thermal energy consumption. The comparison of the conditions and the energy consumption before and after installation of the Parallel Pre-heater fan are as below:

Parameter Before Implementation After Implementation

Clinker Production 3000 TPD 3200 TPD

DP across Pre heater 880 mmWg 860 mmWg

Pre heater fan Power 12.67 kWh /ton<>

Heat Consumption 790 kCal / kg 780 kCal / kg

The implementation of this project resulted in a power saving of 0.6 units / ton of Clinker, which annually amounted to 10.80 lakh units / year. Additionally there was also the thermal energy reduction of about 10 kCal / kg. The increased output of 200 TPD of clinker also aided in reducing the fixed cost component.

Financial analysis

The total benefits amounted to a monetary annual savings of Rs. 50 lakhs. The investment made was around Rs. 10 lakhs. The simple payback period for this project was 2 months.

Benefits of additional P.H. fans