AGROMETER

In the agro-industry, it is large, heavy and expensive machines that characterize the landscape. The same goes for Agrometers agricultural machinery - and it presents some challenges. Therefore, the machine factory, which manufactures large self-propelled and tractor-driven manure spreaders for the agricultural sector, has had Kirkholm redesign and optimize a hose reel. The drum that holds the hose through which large amounts of manure flows is 3.5 high, 2.5 meters wide and weighs 1500 kilos. When the drum is rolled up completely with a hose filled with manure, it weighs up to 10 tons.

SEVERAL BENEFITS WITH MODULE STRUCTURE

The primary challenge with the existing hose reel was that all components were welded together. Because they were so large, they were impractical to move from one location to another. Therefore, the new design is built up in modules, which can easily be assembled where the complete machine is mounted.



- The modular design offers many benefits from production, assembly and not least service when the machine has come out to run in the field, says Kirkholm engineer Robert Eriksen, who has more than 15 years of experience with construction and dimensioning of agricultural machinery.

COMBINATION OF FIVE CALCULATIONS AND EMPIRICAL MEASUREMENTS GIVE GOOD RESULTS

The strength of the hose reel and the material consumption are also optimized. The drum has become lighter and the sides have become 25% stiffer to better withstand the enormous forces that come from the hose when it expands under high pressure.

- With finite element or FEM calculations, we have examined the strength of the construction. One of the challenges of making FEM calculations is to determine what and how much forces the structure is actually exposed to. To begin with, we did not manage to estimate it correctly, and therefore the sides of the drum became too soft and gave way when the pressure increased, Robert explains and continues:

- We made some empirical measurements of how much the hose expands. In fact, the pressure in the hose rises up to 18 bar - by comparison, the pressure in an ordinary faucet is around four bar, says Robert.



Finally, Kirkholm made a reference calculation on the existing construction. Together with the empirical measurements, it was possible to obtain a significantly better estimate of the forces. This meant that it became possible to calculate more precisely how much the sides of the hose reel had to be reinforced.

QUALIFIED MANPOWER IN PRESS SITUATION

According to Kaj Grove Poulsen, construction manager at Agrometer, the project has reached its goal with the right competencies and dialogue, even though there have been challenges in the process.



- The primary advantage of using Kirkholm has been that we have been given some qualified manpower in a pressured situation and some competencies that we do not have at the same level. Throughout the process, Agrometer has had a good dialogue with Kirkholm. We feel that we have had a good understanding of the task and the challenges that lay in it. Despite the fact that the task was not completely successful from the start, Kirkholm lived up to their responsibilities and drove the project to the finish line, he explains.