CASE STORY

The perfect mix for the cement industry: Saving money, energy and CO

2

When Finland’s only producer of cement, Finnsementti, needed to replace its flue gas waste heat recovery equipment, it turned to Alfa Laval Aalborg for a cost- effective, energy-saving solution with a return on investment of less than a year.

Parainen, Finland

Finnsementti’s Parainen plant is located on the South-Western coast of Finland. When their existing flue gas waste heat recovery (WHR) boiler reached the end of its lifecycle, project engineer Berndt Karlsson start-ed sourcing for a replacement that had to fit into the existing limited space: “We were looking for a WHR boiler with better output, and the task was complicat-ed because of tight space restrictions.”

The Aalborg WHR boiler solution

With tentative plans to replace their flue gas WHR equipment, Berndt Karlsson contacted Alfa Laval Aalborg’s sales manager Suvi Luoti.

“We agreed to do some evaluations and calcula-tions, and presented Finnsementti with our proposal. The Aalborg AV-6N water tube WHR boiler has an optimised heating surface, improved output, and we were able to design a boiler that fit into the limited space available at the customer site. After follow-up discussions and meetings, they made the decision to replace their WHR equipment and we got the order,” says Suvi Luoti.

Berndt Karlsson says that there were several reasons why Finnsementti chose Alfa Laval Aalborg. “We con-sidered several flue gas WHR solutions. Yet Alfa Laval

Aalborg had a customized unit that was cost effective and could be easily installed.”

Reduced costs and CO2 emissions

Finnsementti is now using less water and energy and has been able to reduce its CO2 emissions. Energy recovered from the flue gases is used in district heating for the plant, with excess heat being sold to the local town’s district heating network. Without the WHR boiler solution, oil would have to be burned in a fired boiler in order to create the same amount of heat.

“With the outlet temperature now being lower, less water is needed in the conditioning tower for flue gas cooling. And besides the reduction in our CO2 emissions, we’re saving a significant amount on costs with the WHR boiler compared to generating the same amount of energy with an oil-fired boiler,” says Berndt Karlsson.

In addition, pressure drop is taken into account in the design. With lower pressure drop over the boiler, the fan motor uses less electricity, which saves on energy costs.

Easier maintenance

When it comes to maintenance, Alfa Laval Aalborg’s WHR boiler is convenient, for instance with several manholes in the boiler construction that allow for inspections. In

CASE STORY

PEP00045-2-EN 2008Alfa Laval Aalborg Oy

tel. +358 10 838 3800, email: sales.rauma@alfalaval.comUp-to-date Alfa Laval contact details for all countries are always available on our website at www.alfalaval.com Alfa Laval reserves the right to change specifications without prior notification.

About the solution

The Alfa Laval Aalborg AV-6N is a robust, highly efficient waste heat recovery boiler that im-proves a plant’s total efficiency.

With the Aalborg AV-6N, waste heat from flue gas is recovered from sources such as industrial processes, diesel and gas engines or gas tur-bines, in order to generate steam and/or heated water. The solution ensures flexible operation and is easy to install – even at existing facilities.

Fast facts

The customer

Finnsementti Oy is Finland’s only cement manu facturer. The majority of the ce-ment supply in Finland is produced by Finnsementti’s Parainen and Lappeenranta plants. With 100 years of experience, the company produces a consistent quality of ce-ment, and offers a range of concrete admix-tures and additives, as well as crushed rock.

The challenge

Finnsementti needed to replace the flue gas waste heat recovery boiler at its Parainen plant. Space for the new equipment was limited by the existing layout of the plant.

The solution

The Aalborg AV-6N water tube WHR boiler was designed for the limited space available and the flue gas conditions at the Finnsementti plant. It recovers waste heat from flue gas, and heats water to 115°C for use in the plant’s district heating system. Excess heat is sold to the local town for district heating.

The benefits

• Return on investment of less than one year • Manholes and a special tube side design

simplify maintenance • Recovered energy means reduced CO2

emissions and lower fuel costs

addition, the boiler is equipped with soot blowers for automatic cleaning during operation.

Finnsementti’s maintenance engineer Jörgen Björkqvist was satisfied with the solution. “Alfa Laval Aalborg provided us a tailor made solution where our ideas were taken into account. For instance, it is possible to isolate part of the tube sections during use when necessary.”

A good partner

Berndt Karlsson is pleased. “Our relationship with Alfa Laval Aalborg is very good, in fact it couldn’t be better. We greatly appreciated that we could visit the factory and see the boiler before delivery.”

According to Berndt Karlsson, the project ran smoothly. “From the very beginning we have had an open coop-eration, and it has been very easy to communicate with the people involved from Alfa Laval Aalborg. The project ran according to the agreed timeline, and it went quickly with no problems.”

The financial aspects match the technical advantages and the smooth implementation of the project. “The return on investment is less than one year,” says a satis-fied Berndt Karlsson.

Flue gas WHR boiler

Cyclones

Raw mill

Electric filters

Chimney/ Stack

Conditioning tower

Waste heat recovery process at Finnsementti Oy.

Fan

Fan

Fan

Flue gas from furnace

Furnace

The Aalborg AV-6N WHR boiler prior to installation, with manholes and soot blowers visible.