Case Studies

Project
The Bloemenveiling Flora flower auctions in Rijnsburg, the Netherlands, is one of the world's major nodes in the international flower trade. A crucial phase of the logistics process involves the repackaging of the bunches of flowers supplied in boxes into buckets. Bloemenveiling Flora chose PROFIBUS DP for the automation of this time-critical labour process.

Solution
The automation of the new line focused on the automated transport of empty and full containers to and from the production line. The only manual operations required with the new system involve the removal of the flowers from the boxes and their transferral to the buckets. Users at each workplace can choose from three types of buckets. The installation then ensures that the selected bucket, filled with water and supplemented with pre-treatment agent, is delivered to the workplace in manner that takes account of ergonomic requirements. The entire machine has a capacity of 5,000 buckets per hour. A pressure-water installation fills the buckets with the correct amount of water and pre-treatment agent. 'The valve in the water-supply line is opened for 2 seconds. However things are very different with the metering of the pre-treatment agent'. The Bloemenveiling Flora flower auctions make use of two types of pre-treatment agent. John Schols explains: 'Since the agent is supplied in an extremely concentrated form we need to add no more than 2.4 ml to each bucket, equivalent to 1% of the total contents. The metering system may not be vulnerable to stoppage, so we cannot make use of a small slit in the metering head. For this reason we have to open the metering valve for no longer than four thousandths of a second. This is the most time-critical operation that has to be performed with the PROFIBUS system.'

Conclusion
The user: 'In contrast to the former system, the new workplaces can accommodate not only one but two employees at the same time. Our import department has already informed us that the efficiency has been improved by some 20%. These plans were developed entirely in-house, and Flora are the first auctions to have implemented these improvements.'