Flowers like it cool
The flower market is blooming. Whether green plants or cut flowers – the demand is increasing at high speed. The Netherlands is the largest producer and supplier in the world, thanks to “FloraHolland”. The cooperative is made up of growers, flower auction houses and exporters and is the world market leader. Around 11 billion cut flowers were auctioned off in 39 auctions at “FloraHolland” in 2007. To meet the increasing demand, the cooperative makes regular investments in new locations and continually expands its storage capacities. For its cooling needs, the Dutch cooperative relies on high-performance Air Coolers from GEA Küba.
Cut flowers are perishable goods and make special demands on refrigeration engineering. Directly after harvesting, the plants are taken to the draft-free cold storage where they are stored at a relative humidity of 80% in buckets full of water at +2°C, +8°C or +16°C, depending on the type of plant, until their sale the next morning at one of the auctions.
“FloraHolland” invested in the double-digits of millions of euros in their Rijnsberg location, doubling the storage area of the export branch there. The necessary free space was not available for a large-area extension, so a decision was made to put in an intermediate ceiling in the existing building and to double the storage area by 10,780 square metres without interrupting operations. The roof construction had to be raised by some metres to do this.
This was a real challenge for the plant manufacturers of GEA Grenco. The low construction height did not allow standard Air Coolers to be installed. In addition, the airflow would pass relatively closely to the top of the blooms due to the low ceilings. High-performance Air Coolers with simultaneously a low air speed were therefore required. The planners found the solution in the DZ Air Coolers, especially
adapted for this application, by GEA Küba. The high-performance Air Cooler is characterised by low-noise operation, a low airflow and a cooling capacity of 20 kW. The low airflow reliably prevents any formation of condensed water droplets on the blooms or leaves. This is important since condensation forms a breeding ground for fungi which would quickly destroy the flowers..
To reduce the construction height of the Air Coolers, the mounting brackets and the condensing water connection were modified. The drip trays could be folded down and thus can be cleaned easily and quickly. This simplifies handling in everyday operation. A total of 217 GEA Küba Air Coolers have been installed over the two floors.
The consultants installed an insulated room on the top floor of the building for computer assisted control, the emergency power generator and the central refrigeration system. To ensure that there would be dependable cooling over both storage levels independently of one another, GEA Grenco installed a system with two water-cooled model FX PP 2 x 1100 GEA Duo Pack Ammonia Chillers with a refrigeration capacity of more than 3 MW. The machine room was been designed to cope with two additional refrigeration systems of the same power in order to reserve capacity for another extension in the future.
The refrigerant system works at -7°C. The frequency controlled pumps circulate 135 cubic metres of a water-ethylene glycol mixture and pump the refrigerant directly to the Air Coolers. Each storage room has its own pump circuit. This ensures that the temperature demands of the various plants and flowers in the different storage rooms are always met. The cooling system was completed and put into operation in April 2008 after a construction time of four years.
“FloraHolland” installed an automatic transport system in parallel with the new cooling system. This was an absolute necessity to cope with the increased number of products. The increasing demand and therefore greater capacity is being driven primarily by the booming online trade auction. A good 40% of all flowers are now auctioned online, without the bidder even seeing the real flowers. FloraHolland will be investing 80 million euros in a standardised lift truck for all 6 locations over the next few years, to allow them to meet the future demands of e-commerce.
Bloemenveiling Aalsmeer and FloraHolland merged on 1 January 2008. The new cooperative FloraHolland offers growers and customers a network of six branches (Aalsmeer, Naaldwijk, Rijnsburg, Venlo, Bleiswijk and Eelde), a nationwide brokerage office (FloraHolland Connect) and a centrally managed import department. FloraHolland employs 4500 people. It has annual sales of more than 4 billion euros.