The ecoFridge is a cryogenic refrigeration system that uses liquid nitrogen to cool the van and maintain low temperatures. It can bring the trailer down to a set temperature 70 percent faster than conventional systems without top freezing.
When compared to conventional diesel refrigeration systems, the ecoFridge has several major benefits. As it does not require diesel to operate, the ecoFridge produces no direct carbon emissions. At a further benefit to the environment, customers can choose to specify that their liquid nitrogen supplies are generated by renewable energy.
Operating in complete silence means that urban deliveries restricted by noise curfews are no longer an issue as the ecoFridge eliminates the noise of conventional refrigeration systems.
The ecoFridge contains virtually no moving parts so is almost maintenance free, drastically reducing downtime when compared with conventional diesel units.
How it works
Liquid nitrogen (LN2) in the ecoFridge is stored at a temperature of -196ºC in a safe, double skinned low-pressure vacuum tank. The nitrogen goes through an expansion chamber that transforms the liquid into a gas that is then released into the trailer as an almost invisible vapour. Temperature sensors detect exactly how much nitrogen is needed in order to keep the temperature within 1ºC at all times.
ecoFridge Sales and Marketing Director, Liam Olliff, travelled to Melbourne from the United Kingdom to explain the ecoFridge to show visitors. He said, “The ecoFridge actually keeps temperatures better than a diesel refrigerated system. It can get to a set temperature point 2.5 times faster than a diesel refrigeration system.”
A control box located at the front of the van contains all the electrical components required for the ecoFridge system to work. Two marine rated batteries allow the system to operate independently of any external power source for approximately 20 hours, before recharging is necessary. An automatic trickle charging system, powered by the van’s running lights, will also be available to maintain battery charge indefinitely if the van is hitched to a truck.
Nitrogen makes up 78 percent of the air we breathe and is completely harmless when in contact with food. While it is not dangerous as an inert gas, it only presents a handling issue as it disperses O2 into a sealed environment. Operators should therefore be aware of the simple precautions assocaited to its use.
The ecoFridge system employs three independent safety devices: audible driver alert, a red light and a failsafe locking cable to ensure that safety is never compromised.
In the ecoFridge system, nitrogen can only be released when the van doors are fully closed. When the doors are opened, the oxygen analyser and warning system automatically check the internal atmosphere and restrict entry until the required oxygen level is achieved which is indicated by a green light inside the van. When the doors are first opened, a red flashing light and audible alarm alert the operator that they cannot enter the trailer and the safety cable prevents the operator from entering until oxygen levels reach the safe level of 18 percent. Once the doors are closed again, the system automatically restarts. If an operator were to become trapped inside the trailer, pressing an independently powered illuminated stop button inside the trailer will instantly close the system down and show audible and visual external warnings.
The 1000 litre nitrogen tank located beneath the trailer is expected to provide operation times of around 30 hours or more between refills, making it also suitable for line haul use.
Refuelling can be provided through a static storage tank or a mobile delivery system, whereby a hose is connected to the vehicle and the liquid nitrogen is fed into the tank. This process takes approximately 10 minutes.
Currently, liquid nitrogen is available from three major suppliers in Australia, however users of the ecoFridge can install bulk supply tanks at key distribution warehouses.
Liam adds, “Every litre of diesel burned produces 2.63kg of carbon emissions. Every trailer with a diesel refrigeration unit produces 25-30 tonnes of carbon emission per annum.”
The ecoFridge is suitable for all trailer and temperature zone configurations, including dual temperature zones.
The future of the ecoFridge
The concept of cryogenic refrigeration is actually not a new idea. Nitrogen has been a familiar fuel/coolant to the food industry for many decades and was in fact first developed in the United States during the 1960s. However, as safety concerns and litigation became more prevalent, technology struggled to keep up and many manufacturers stopped making it.
ecoFridge was formed in the USA in 2000, spending the first seven years in research and development before releasing the first refrigerated trailer unit two years ago. Its main assembly is now based in the Ukraine with operations in South Africa, France, Israel, United Kingdom, North America, and more recently, Germany.
Since the product was launched, many prominent companies have started to use the ecoFridge including, Asda (UK), Carrefour (France), Safeway (USA), and Woolworths and Pick ‘n’ Pay (South Africa).
Whilst MaxiTRANS is still conducting field trials on the ecoFridge system to determine operating costs and full performance data under Australian operating conditions, MaxiTRANS has plans to soon make the ecoFridge available to Australian and New Zealand operators as part of its continued commitment to provide customers with first grade transport solutions.
MaxiTRANS Australia also received the ‘Most Unique Show Attraction Award’ for the ecoFridge at the 2010 ITTES Expo Awards that were held on Saturday, 20 March.