Refrigeration / Distribution Centers

From its headquarters in Weeze, the company supplies the catering and hotel trade throughout western Germany, as well as canteen kitchens in senior citizen homes, hospitals, educational facilities, and company catering with everything required in and around the kitchen. The assortment comprises about 20,000 articles – from frozen foods to fresh goods, processed foods and dry assortments, and up to cleaning and hygienic products as well as canteen kitchen accessories. The company is currently expanding its coldstorage capacities in order to reliably serve the continually rising demand. To assure longterm, reliable refrigeration, the systems contractor installed 23 Kelvion, including 13 Küba market SP evaporators and one SG commercial. The building extension is a refrigerated distribution warehouse with more than 4,500 m² fl oor space, primarily for fresh supply service, milk products, and fresh fruits and vegetables. Apart from individual small cold-storage rooms, the core facility is a high-bay warehouse with a height of 11.5 m.

As a rule, the fresh goods remain here for less than a week before being delivered by the company’s fl eet to the customer. Christoph Peters, Managing Director of Kälte Klima Peters GmbH, with home office in Meerbusch (Germany), installed the refrigerating system according to planning specifi cations. Christoph Peters: “Fruits and vegetables are perishable goods that, depending on variety, place a great variety of requirements on refrigeration engineering. It is crucial to observe a narrow range of temperatures, minimize air drafts, provide optimal indoor climate, maintain ideal humidity for fresh fruit, and assure the highest hygiene level for optimum quality during warehousing. In addition, the greatest possible operational reliability and low operating costs are of prime importance.” The refrigeration of fruits and vegetables results in formation in the air of acidic aerosols, which are quite aggressive. Especially around the evaporator, where such aerosols can lead to turbulence, they attack the external casing and leave deposits inside. “It is therefore important that the casing is made of stainless steel in accordance with VDI standard 60.22, and both the drip tray as well as the fan must be hinged to enable rapid and reliable cleaning of the evaporator. The new Küba market SP fan units are hinged as standard. This was one reason for me to install Kelvion evaporators here,” says Peters, who has specialized in large-scale projects.

A second crucial factor recommending the Küba market SP was the confi guration software from Kelvion. Peters: “After the parameters are entered, the program Küba Select makes it possible to compare the sound pressure levels of various Air Coolers in tabular form to systematically include the background noise of the refrigerating system in the total calculation. This is very important for many of our projects – because we always want to install quiet equipment with a maximum of 60 dB (A).” In future, the Kelvion evaporator in Weeze will emit no more than 40-50 dB (A) while running. “These are ultra-quiet coolers,” says Peters, and emphasizes: “It reduces sound pollution for the warehouse staff to almost zero. And we minimize plant power requirements at the same time.” Energy effi ciency is achieved by an optimally calculated ratio of the fi n surface to fan area. “In general, systems contractors reduce the fi n surface and install large fans. What might seem to provide savings potentials at fi rst glance, upon more precise calculation proves to be an energetic cost driver and propels background noise to new heights. This is because temperature fl uctuations due to restocking the cold-storage warehouse inevitably lead to the fans running loudly under full load. This impairs the quality of the goods and stresses the employees,” says Peters, who has decided to take another route and is keeping long-term investments in mind in his systems planning.

Concerning cooling capacity and air throw, the evaporators are designed so that they do not approach their limits – even after extended infl ow of outdoor warmth – therefore keeping DT1 small. To reduce pressure loss and keep the associated power requirements to a minimum as well, Peters ordered evaporators with patented refrigerant distributors from Kelvion. “The distribution of the refrigerant is excellent, and with the right design the slight pressure loss does not require energy compensation.” The refrigerating system is connected to the PLC plant with software from Peters, ensuring permanent synchronization of data. In parallel the plant is coupled to an external server located at Peters’ offi ce, to which it sends a signal every hour. If a signal is not received, the monitoring software automatically radios the service technician. This is an additional safety feature. For defrosting in the above freezing range, Peters uses hot gas, since electric defrosting by optionally installed heaters would consume additional primary energy. The PLC plant also constantly monitors any frost build-up on the fi ns. Since both evaporators as well as the installed condenser have controlled EC fans, they can be reset at two places at all times to ensure optimal cooling duty with minimum drying of the chilled goods, and to protect freshness and quality.