Plant upgrades are critical for enhancing manufacturing capabilities, reducing cost of production and curbing emissions.
Over the years, the cement industry in India has grown exponentially, and it currently faces challenges like the need to improve energy efficiency, maximise capacity, eliminate bottle¡necks, reduce cost of maintenance, switch fuels, and many more.
In the recent past, new greenfield and brownfield plants, with lower levels of specific fuel and power consumption, have set new benchmarks. Again, with fuel and power becoming more expensive, the cement industry is poised for a makeover. Technological advancement and innovative solutions have helped overcome the challenges and optimise resources.
The reasons for plant upgrades and modifications are not generic across the cement industry, and are plant specific. Some of the prominent reasons are:
1.To meet the growing market demand in a region
2.To enhance the production capacity
3.Reduction in cost of production
4.To meet the government regulations on emissions levels
5.Adopt energy efficient technologies.
Challenges in Upgrades
Retain existing setup: Maximise the possibility of utilising existing building and retain the existing equipment.
Limited space availability: Customise new machinery within the available space. Delivery time: Accommodate short deliveries in line with the plant annual shutdown schedule.
Plant engineering: Customised solutions and innovation in fitment of new equipment. Civil design: Unwarranted changes during project execution due to limited information of the existing plant.
Interface: Minimal modifications in the interface areas.
Erection & commissioning: Detailed scheduling of shutdown activities in order to meet stringent timelines for erection and commissioning of the new equipment to minimise the downtime.
Installation: Facilitate any modifications for fitment of new equipment in limited time and access.
Trendsetting ongoing upgrades in the industry by FLSmidth
Project 1 (Refer to Figure 1)
This upgrade project was taken up to increase the production of the pyro-processing system from 4,150 tpd to 5,000 tpd and reduce the fuel consumption by 70 kcal/kg clinker. In the first phase, latest generation high efficiency FLSmidth® Cross-Bar® 14 x 47 cooler was installed. In the second phase, a new six-stage ILC low NOx preheater tower will be installed in front of the existing tower above the kiln. This new preheater string will be rated for 1800 tpd nominal. The existing four-stage Separate Line Calciner (SLC) preheater tower will be de-rated to 3,200 tpd clinker production, so that the heat transfer efficiency becomes better and the pressure drop across the existing tower is maintained at optimal level. Thus both the existing preheater string and the new preheater string are made optimum towards lesser energy consumption (under execution).
Significant benefits expected of this project are:
Project 2 (Refer to Figure 2)
The upgrade project´s target is to make the older line on par with the new line in terms of capacity and energy efficiency. Hence to match the new line capacity, an additional tower with the cooler change became inevitable. The new tower had limitations in tower height and hence by proposing a twin-string ILC for the new tower, the height limitation factor was addressed. The old tower will be de-rated to its original capacity of 2,500 tpd and the new tower will be operating at 2,100 tpd to produce 4,600 tpd clinker production in total (under execution). The upgrade includes the installation of latest generation high efficiency FLSmidth® Cross-Bar® 14 x 43 cooler, modification in kiln drive and additional coal dosing system for the new balancing tower.
Project 3 (Refer to Figure 3)
There is an existing five-stage single string suspension preheater tower and a new five-stage single string ILC low NOx calciner together for 1,900 tpd clinker production. The equipment also comprises an ATOX™ 35 mill system for raw material grinding, RTKM separator for existing coal mill and latest generation high efficiency FLSmidth® Cross-Bar® 8 x 36 cooler.
The above upgrades have driven the technological knowledge base to innovate and bridge the gaps with seamless solutions. These are indeed trendsetters in the industry.
Leaving aside the aspect of maximising the capacity and reduction in cost of production, the rapidly shooting climatic changes owing to the greenhouse gases emission is a concern at large for mankind. Carbon dioxide is a main contributor to greenhouse gas which emanates from cement plants.
In a typical 5,000 tpd clinkerisation plant, if there is a potential to save 50 kcal/kg cl fuel savings, we are going to bring down the greenhouse gas emission by ~30,000 tonnes of CO2 per annum. In addition, growing costs of resources are leading to the possibility of modernisation, optimisation, retrofit or upgrade in a plant and there is immense scope at cement plants in India.
While one decides to take a step in this direction, the following aspects can be looked into:
(This article has been authored by Logesh Baskaran, FLSmidth, Senior Manager - Sales, Products & Upgrades).