Drying machines uses novel air jets

Applying pneumatics to a novel container drying machines is helping companies to cut waste and improve throughput. Dean Palmer reports A small, three-man engineering design firm has developed a range of novel container de-watering machines, based on its own innovative pneumatic air jet technology. The developments are specifically aimed at the food and drinks manufacturing industry and are already helping major European companies to reduce waste, noise levels and improve the uptime of conveyor lines. According to its customers, the new machines are an effective, reliable, energy efficient alternative to using air knives. The company responsible for the developments is ON Beck (www.onbeckltd.demon.co.uk) based in North London. The firm's new 'Mistral' de-watering system uses multi-directional, high velocity air jets or nozzles to atomise the water droplets and remove them from critical areas of containers. These critical areas are underneath crown corks on bottles, ring pulls on cans and the sides of jars that require drying before sleeving. The air jets are enclosed in an aerodynamic hood assembly or tunnel, the mist being extracted by Beck 'Ringjet Airmovers' and extracted to a drain. Additional jets are then used to further dry the necks or sides of the container. Total coverage of the surface and effective drying is made possible by Beck's patented method of movement of the container surfaces relative to the air jets. The machines, which are made entirely from stainless steel, can be easily attached to a conveyor and customers have fitted the unit to the line themselves. And to cope with different size containers, the height of the drying machine jets can be adjusted in seconds to an accuracy of a fraction of a millimetre. At the core of all Beck's innovations are bladeless, motorless fans that act as volumetric air amplifiers. These 'ringjets' convert low volume high pressure compressed air to high volume, low pressure air. They have no moving mechanical parts or shims and are operated by compressed air to provide the capability for either blowing or extracting. The devices are adjustable and suitable for hazardous areas and are virtually maintenance-free. The real innovation comes from a special design of jet that amplifies the compressed air supply by around 25 times. In other words, if you put in 1 bar, you get a 25 bar output of air. Different customers in the drinks industry will obviously require different de-watering machines, so Beck has ensured that each unit can be easily customised with a range of accessories. There is an in line compressed air drying unit to maximise the drying process and 'Airminder', Beck's electronic control for 'supply on demand' of air, which gives maximum efficiency of air usage. There are also warning systems that provide shut down or audible and visual alarms. The in built sensor alerts the control unit to cut off the supply of air when gaps occur or objects are stationary on the conveyor line. A pre-determined delay is programmed into the control and instantaneous start-up of air occurs when a moving object is sensed again. In this way, air wastage is minimised and unnecessary noise is eliminated. According to Clifford Beck, MD of ON Beck, "The Mistral has already proved itself during months of testing under extreme conditions of both moisture coverage and line speed at several major European food and drink companies. The machine was also a finalist in the 2000 London Innovation Awards and won a Smart award recently." Last year, soft drinks giant Britvic launched a complex shaped plastic bottle for its new-look 'Tango' drink but experienced drying problems around the bottle's curvaceous neck profile. The curved profile holds water making it difficult to dry using conventional air knives and resulted in the inkjet print rubbing off. Stuart Brand, engineering team leader at Britvic's Becton plant, looked to Beck for a solution. He explained that equipment was needed to dry bottles travelling along the plant's conveyors at a rate of 800/minute. He told Eureka: "The Mistral works fantastically and without it we cannot run this shaped bottle." The company has also designed a larger unit, the 'Zephyr', specifically aimed at manufacturers that require a reliable, energy efficient, low noise output machine. Waste water disposal was also a key design factor and the machine can cope with increased line speeds of up to 1,000 containers per minute. The noise level is low at only 79dB(A) at 1m. The third model in the range, 'Sirocco', is a medium size de-watering unit for containers on a conveyor line, with speeds up to around 500 bottles per minute. The patented machine uses a combination of sonic velocity air jets and Beck amplifying Airmover to remove all traces of water droplets from the containers. In the late 1960s and early 1970s, Beck made its name by designing and manufacturing fans and blowers for the marine industry, special units for coal mines and standard devices for general industrial applications. The company now supplies all kinds of industries including oil and gas, chemicals, food and beverage, plastics and toy manufacturing. In 1999, the firm developed a clever device (which Eureka covered in its April 1999 issue) called a 'Coanda' jet, after the person who developed the theory of fluid amplification, Henri Coanda. Basically, the jet design had an angled lip inside which draws compressed air down its sides at greatly amplified speeds (a ratio of 1:25) and out from the nozzle. Most of Beck's developments to date are based on this solid design principle. The proof is in the statistics of units sold. According to Clifford Beck, "Rolls Royce aero engines have purchased more than 2,000 of these jets for their production plant, to help improve compressed air efficiency, improve safety and reduce noise levels. Cadburys also uses the devices for cooling applications." He added that the Royal Navy has also bought hundreds of custom designed, portable monojet versions for ventilating its nuclear submarines. And, after those contracts, orders also followed from airline companies such as BA and Lufthansa. Other major clients include Coca Cola, Scottish Courage, Carlsberg, Heinz, Nestle, Van Den Bergh and KHS UK. The idea for using the air jets in machines for the drinks industry came back in 1996. David Dell, senior project engineer at Beck and senior lecturer aerospace, automotive and design engineering at Hatfield University, told Eureka: "We developed a test rig because many drinks manufacturers were suffering from rejected bottles that had corroded metal bottle tops because of water finding its way under the rim during production. The air knives that many manufacturers were using were simply not removing all the water during bottling." He went on to say that a more scientific approach was needed. "The increasing demands on food and beverage manufacturers for total traceability was also becoming an issue. Labels stuck onto bottles cannot be achieved if water is present on the sides. The same goes for 'best before' dates on the bottom of containers and cans. You can't inkjet these on if water is present." The potential applications for Beck's pneumatic air jets and de-watering machines are numerous. Clifford Beck suggested plenty, including the rapid cooling of castings; quick drying of chocolates; extracting swarf and oil mist, removal of paper dust and trim, fresh air delivery; cooling paper products; removal of paint or welding fumes; drying crates after cleaning; and cooling plastic injection mouldings. The list goes on and on. To date, ON Beck has spent more than £35,000 on patents covering most of the world, including the US, Europe, China, India and Russia.