The Tan Dong Son Company Limited based in Vinh Loc B Commune, Binh Chanh District, Ho Chi Minh City specializes in producing steel billets and finished steel products for use in the field of civil engineering. Along with making efforts to develop production and business activities in order to improve its competitiveness on the market, the company actively seeks ways to reduce energy consumption so as to lower the production cost.

With an annual production output of 7,000 tonnes of steel billets and 10,000 finished steel products, Tan Dong Son consumes about 7,500kWh of electricity and more than 900 tonnes of coal each year. To cope with rising energy prices, the company has taken many measures to restrict the use of electricity and coal during the production process.

With assistance of the Institute of Energy Sciences under the Vietnam Science and Technology Academy, the company has been aware of the great potential for energy conservation. Apart from simple solutions such as improving management and human resources, the company has decided to take technological solutions that require big investments.

Simple solutions

To operate a production line with modern technology safely and efficiently, workers must be equipped with good technical knowledge. Aware of this, the Tan Dong Son Company Limited has recruited specialized technicians and engineers to supervise each stage of the production process to ensure safety and energy efficiency.

The company has provided its workers with simple books so that they can learn necessary technical knowledge. In addition, the company has organized training courses on energy conservation to improve the awareness of workers in this field. Those individuals that achieve good energy conservation results will be rewarded on a timely basis as examples for others to follow.

The results of a survey that was conducted at the steel plant of the Tan Dong Son Company Limited show that the amount of time in which the engines operate at the no-load status is very big, causing losses of more than 126,000MWh of electricity or about VND169 million each year. If this problem is resolved, the company can save an estimated VND84 million each year by reducing the time of no-load operation of engines by a half.

In the steel tempering process, if the no-load operation time is reduced by about 15 minutes for every batch of steel products, the company can save about VND350 million each year.

To better manage the use of energy, the company has set clear norms for consumption of each type of energy such as electricity and coal at every production stage and for every kind of products.

For a steel plant, actually, it is impossible to avoid 100 percent of the losses caused by no-load operation of the engines. The solution that Tan Dong Son has chosen to overcome this problem is using Powerboss inverter.

It is estimated that if the company installs one Powerboss PBI 280 inverter to the engines that are used to make crude steel products and one Powerboss PBI 220 inverter to the engines that are used to make refined steel products, it can reduce power consumption by about 25 percent to save more than 155,000kWh of electricity or about VND160 million each year. This solution requires an investment of more than VND283 million.

Some other solutions that can be taken to reduce the amount of electricity and coal consumed by the furnace during the steel production process are: regulating the speed of the fan, replacing the bricks at the outer layer of the furnace and narrowing the door of the furnace. These solutions can help the company save more than VND500 million each year. However, they require big investments.

It is estimated that to replace the bricks at the outer layer of the furnace to reduce heat losses, the company has to invest more than VND130 million, which can be recovered after nearly two years.

As a result of its efforts to boost production and protect the environment, from a small-sized business, the Tan Dong Son Company Limited has become one of the largest steel producers in Ho Chi Minh City.

By Nga Nguyen