FOCUS. All-out energy-saving. Reference Plastics and rubber industry EFFICIENT REFRIGERATION TECHNOLOGY IN ACTION

Transcription

1 Reference Plastics and rubber industry All-out energy-saving EFFICIENT REFRIGERATION TECHNOLOGY IN ACTION

2 Moens Mouldings B.V., Beverwijk (NL) (1) The open-air chillers on the container roof draw the cold needed from the surroundings. At low temperatures this leads to dramatic energy savings. The Dutch plastic processor Moens Mouldings B.V. has put a new refrigeration plant into operation at its Beverwijk location (near Amsterdam). L&R Kältetechnik GmbH & Co. KG, together with its Dutch partner Kurval TRS B.V., planned and installed a plant that not only allows clear energy (cost) savings of over 60,000 annually, but also creates the preconditions for a significant boost in productivity. Economy or ecology which comes the company s carbon footprint. It also generates the desired temperature level with first? When it comes to refrigeration technology in plastic processing, this greater precision, thus accelerating the question does not arise. This is because cooling process and in this way creates the what makes ecological sense is also good conditions for shorter cycle times, which in for the bottom line: an efficient refrigeration turn boosts productivity and cuts production plant does not just save energy and reduce costs. Innovative packaging and disposable articles Moens Mouldings B.V., which develops and produces high-quality injection mouldings at three locations with about 100 employees, now benefits from these advantages. Among other things, its product range includes disposable packaging with innovative closing technology, which can be opened and closed with one hand and disposable cutlery and glasses made of polystyrene. The company group processes about 6500 tons of material annually. As a socially responsible company it strives to reduce the environmental effects of its production to a minimum. At its Beverwijk location there was a refrigeration plant for mould cooling that was about 15 years old. Groundwater was used to cool the hydraulics. Since the temperature control demands of modern machines and tools are steadily increasing and Moens wanted to improve the efficiency of its refrigeration technology too, those in charge of planning decided on a new refrigeration plant. They commissioned Kurval-TRS B.V. for this. As the Dutch distribution and service partner of L&R Kältetechnik GmbH & Co. KG, Kurval possesses wide-ranging know-how in refrigeration technology and also supplies the plastics industry with other components, such as conveyance systems, grinding plants and driers. As a result, it combines technical and sector expertise. Winter discharge saves energy costs The L&R engineers planned an air-cooled refrigeration plant with two adjustable Bitzer screw compressors and a total refrigeration capacity of 400 kw for mould cooling at a flow temperature of 15 C. In the summer, two automatic open-circuited open-air chillers without glycol admixture handle the hydraulic cooling for the injection moulding machines (Figure 1). During 2 3

3 Refrigeration units with two adjustable Bitzer screw compressors; 400 kw total cooling capacity. (2) One of the three operational pumps for the tool and hydraulic circuit is equipped with an electronic speed regulator. This ensures that the pump capacity is adjusted precisely for the current need. the transitional period, i.e. at temperatures below 15 C, the hydraulics are cooled by only one open-air chiller. The second openair chiller is then used for partial relief of the refrigeration plant. At ambient temperatures below 10 C the second open-air chiller even assumes the entire refrigeration capacity of the refrigeration plant. This means that at temperatures below 10 C, the cold required is obtained entirely from the environment. The economic advantages of this technology, also known as winter discharge, can be calculated very precisely and L&R made them clear in its bid. The savings to be expected from the winter discharge are over 50,000 annually if one assumes 6000 operating hours and an electricity price of 0.12 /kwh. In view of this sum, Moens had no difficulty in deciding on this option, which promised the fastest amortisation. Flexible condensation temperature control The existing refrigeration plant like most refrigeration plants operated at a fixed condensation temperature, normally about 47 or 48 C. However, this temperature is only required at very high outdoor temperatures of approximately 35 C. Hence the plant operates on worst case refrigeration assumptions, which only occur on a few days in the year. In energy terms, it makes more sense to adjust the condensation temperature to the actual outdoor temperatures. L&R Kältetechnik created this feature with its Vari- Kon control. It lowers the condensation temperature for most of the annual operating period and reduces the operating time and power consumption of the compressors correspondingly, resulting in reduced energy consumption overall. For example, at an outdoor temperature of 10 C the plant runs at a condensation temperature of 23 C and not 47 C. Worthwhile energy saving measures L&R pointed out this energy-saving measure to Moens, which is especially efficient in combination with winter discharge. The annual energy cost saving calculated here amounted to over 60,000 annually. This must be balanced against investments in the open-air chillers, temperature-sensitive control and the accompanying sensors. Moreover, the refrigeration plant then has to be fitted with electronic expansion valves and electronic, speed-controlled fans. Nevertheless, the flexible condensation temperature control pays for itself in a short time span, thanks to the great energy savings, while Moens saves energy costs permanently. 4 5

4 (3) The overall control system of the plant, which L&R develops and manufactures at its own plant, is also installed in one of the two containers. (4) Consisting of two containers, the container system includes the refrigeration unit, pump and tank systems, switch cabinet and control system. Speed-controlled pumps As another energy-saving measure L&R proposed fitting each of the three 22 kw operating pumps for the hydraulic and mould circuit with speed-controlled drives (Figure 2). During low or peak operation the pumps then adjust to the conditions while the other pumps assume the basic load supply with constant operation. This lowers the electric power consumed by the pump motor by up to 30%. Container plant can be quickly assembled The entire refrigeration plant including the control technology (Figures 3+4) was installed in two containers at the L&R Sundern factory; the open-air chillers fit on the container roof. Thanks to this compact, easy-to-assemble design, fast, flexible installation on the company site is possible. Considerable productivity boost as side-effect To guarantee the availability of the plant, Kurval-TRS B.V. provides a 24-hour service, which Moens has not yet needed though. Since it started operations in May 2012, the refrigeration plant has operated without any malfunctions and is also achieving the estimated energy cost savings. From the point of the view of the operator, the reductions in CO 2 emissions resulting from the refrigeration technology s high efficiency are just as gratifying. The operating cost calculations did not even include one effect: the parts made now cool off faster in the mould. The temperature control of the hydraulics can also be fine-tuned. This in turn makes it possible to shorten the cycle times and boost the productivity of the injection moulding machines - over the entire service life of the refrigeration plant. 6 7

5 Competencies MARKKOM.COM PLASTICS AND RUBBER INDUSTRY A plastic-parts manufacturer operating about 100 injection moulding machines recorded frequent machine failures that were caused by the aging refrigeration system. Renovating the system didn't just reduce the number of failures; the improved cooling allowed the injection-moulding machines to operate with shorter cycle times, enabling our customer to increase their output by 10-15%. SURFACE TECHNOLOGY AND ELECTROPLATING An advanced refrigerant, higher cooling capacity and significant energy savings were the objectives pursued by Koenigsdorf Oberflächentechnik GmbH & Co.KG in Wolfhagen when they decided on a new refrigerating system. FOOD PRODUCTION Refrigeration is one of the main energy consumers in chocolate production. Retrofit projects can achieve savings of up to 50% an investment that gives the user a clear amortisation period. L&R Kältetechnik cooperates with two companies that specialise in this sector. CHEMICAL AND PHARMACEUTICAL INDUSTRY We have the best references in the cryogenics sector, including for the storage of blood plasma. For these particularly challenging applications, we plan and design completely redundant refrigeration systems with correspondingly high safety features. SPECIAL UNDERGROUND MINING Ground-freezing systems are becoming increasingly common in mining projects when sinking shafts. A freezing system with a capacity of 3600 KW was developed and constructed for a Russian potassium mining project which cooled cold brine to a flow temperature of -38 C. L&R Kältetechnik GmbH & Co. KG Hachener Straße 90a, D Sundern-Hachen, Germany Tel.: , Fax: DW 50 info@lr-kaelte.de L&R Kältetechnik GmbH & Co. KG Office Frankfurt a.m. Hasengasse 4, D Maintal, Germany Tel.: , Fax: DW 875 Mobil: f.woell@lr-kaelte.de Distribution partner for Netherlands: KURVAL-TRS BV Haverstraat 145, 2153 GB Nieuw Vennep Tel.: +31 (0) , Fax: +31 (0) info@kurval.nl, Responsible for the content: L&R Kältetechnik GmbH & Co. KG Burkhard Rüßmann; design and realisation: MARK KOM Consulting / Lindau (D); Image copyrights: L&R Kältetechnik, Moens Mouldings B.V.