ECHO

‘Our production speed rose by forty percent while our energy cost halved.’

Floor elements have been manufactured at Echo since 1954. The company called on Encon to optimise its production process. Its know-how was also used for the construction of new production lines.

Echo has developed and produced floor elements for the construction sector since 1954. This Limburg family firm has grown over more than half a century into a leading player at the global level. Echo is even the market leader in Belgium and the surrounding countries. Today the group employs more than seven hundred people in over ten facilities. The step towards manufacturing pre-stressed and reinforced concrete has been taken over the years, with the help of new production methods and machines. During the manufacture of pre-stressed hollow-core slabs, concrete is poured onto a so-called ‘production bed’: a steel construction that can be compared with a long bowling alley. The concrete elements are then heated on this bed to accelerate hardening. As soon as the hollow-core slabs are sufficiently hardened, they are taken from the production bed and stored. The production line is then prepared again for the next cycle.

Echo started the construction of a new production unit in Genk in November 2008. This facility was to have four production beds (each 180 metres long and 2.7 metres wide). Encon was called in to analyse and optimise the energy consumption of the existing process in the Houthalen facility in an initial phase. This expertise then had to be applied to the new production lines. The aim here was to reduce production costs to a minimum. ‘We were looking for a method to heat our production beds as efficiently as possible,’ says Jorg Pollaris. He is the technical innovation engineer at Echo and was closely involved in the entire operation. ‘Among other things the optimum speed for the hardening of our hollow-core slabs had to be investigated. Of course, we had to call in experts for this. We selected Encon because of their good references.’

SIMULATION PROGRAM

The Encon engineering team started by mapping the energy costs of the existing production process. The techniques used were also compared with alternative methods for manufacturing concrete hollow-core slabs. It quickly emerged that the bed heating was the biggest energy consumer in the production process. In cooperation with Echo, Encon developed a special simulation program that can simulate heat consumption in various circumstances. ‘Among other things these simulations helped with the choice of the most suitable energy source: gas, fuel oil or electricity,’ says Pollaris. ‘Moreover, the simulation program taught us what the optimum heating bed construction was. It quickly became clear from all of this that cogeneration was the recommended technology for our production units.’

Echo also called Encon in to study and optimise the production speed. A thorough analysis was performed again based on the simulation program. Incidentally, to do this the Encon engineers cooperated with Echo Engineering, a division of the Echo group which develops production machines. To lend weight to the theoretical results of the simulation and to optimise these, extensive measurement campaigns were then also carried out on the existing production lines.

TRIAL DEPLOYMENT

Encon then built a trial deployment of a production line with a usable surface area of one square metre. This enabled the engineers to imitate the production process while simultaneously measuring the temperature profile and energy consumption. To do this the trial deployment was equipped with more than twenty temperature and power loggers. Various measurement campaigns were carried out with different heating settings in each case. Practical conclusions were drawn based on the measurement campaigns on the existing production lines and measurements on the trial deployment. The optimum settings for energy consumption and production speed were then determined based on practical simulations. And to good effect: energy consumption has halved today while the production speed has increased by more than forty percent. In fact it is unbelievable how much money and energy you can save if you allow energy specialists get involved in thinking about the development of your production process.

After the positive results of the simulations, Encon carried out the engineering to heat the production beds. The analyses had revealed that cogeneration is the most energy-saving solution for this. However, it is important for a cogeneration plant of this type to be dimensioned correctly. An over sized installation would be detrimental to profitability, whereas an installation that is too small would not lead to the proposed saving. However, the work hall was still being built at the time. This meant that it was impossible to dimension an existing installation with the help of measurement campaigns. So it was decided to equip the new facility with natural-gas heating boilers in a first phase. However, all steps were taken to allow the integration of a cogeneration plant later. A heat meter was installed at the time so that the system could be adjusted correctly later. This means that sufficient measurement data should be available after approximately six months of production to dimension the cogeneration system correctly.

ENGINEERING IN 3D

Encon then designed the entire heating plant. During this engineering phase Encon created a detailed design in which all of the components were drafted. This resulted in a detailed three-dimensional plan. Jorg Pollaris: ‘The advantage of such a 3D diagram is that it reveals possible practical difficulties during construction in advance so that we can resolve these before everything is actually built. Based on the full file, a set of specifications was then drawn up with an invitation to quote for fitting the entire installation. Despite the complexity of this project the full analysis and engineering were implemented in a period of less than six months.’ Echo Engineering was responsible for the ultimate construction of the new production lines.