IN-PLANT MATERIALS HANDLING  41


Multiple advantages in using tubular drag conveyors


Company (SWDCC) in Burnaby, British Colombia with conveying technol- ogy for decaffeinated green coffee beans. SWDCC prides itself on the quali-


T


ty of its decaffeinated coffee, which is produced using the Swiss Water process. Green coffee is generally considered to be pretty ‘hardy’ when it comes to being handled, but SWDCC observed some deterioration in bean quality within its operation and after extensive research determined that bean de- lamination and breakage was taking place whilst the product was being conveyed. Traditionally, SWDCC utilised pneumatic


conveyors, drag chains, and bucket elevators to convey decaffeinated green coffee beans, but decided it wanted a conveyor that would be gentler on the product; a conveyor that would be able to accommodate multiple inlets and multiple outlets; and a conveyor that was sufficiently flexible to operate in their existing plant layout. Essentially, they wanted a con- veyor that would have the product protection of a bucket elevator (or more), but with the lay- out flexibility of a pneumatic conveyor.


Conveyors and


elevators replaced Responding to SWDCC’s needs, Cablevey supplied a 6in conveyor capable of moving 52,000 lb/hour (23,500kg/hour) of green beans from the outlets of a bank of silos to two pack- aging stations. One Cablevey system replaced three drag chain conveyors and one bucket elevator. Removing the transition points opened up the area considerably due to a reduction in the number of drive units, which also resulted in fewer points of failure and ulti- mately in less product damage. Immediately after commissioning it was


apparent that the Cablevey Conveyor was very quiet, much quieter than the systems it replaced and any other conveyors in the facili- ty. Cablevey’s sealed unit and the continuous


he first application of Cablevey technolo- gy saw the US-based company provide Swiss Water Decaffeinated Coffee


Cablevey conveyors are designed to move products gently and reduce product damage


wiping on the interior of the conveying tubes ensured that the system was kept clean on a continuous basis. Together with the removal of the transition


points, there are now no areas where beans can become caught. Consequently, the oppor- tunities for cross contamination from one batch to another were removed and the clean- out time that was required in the previous sys- tem has become unnecessary.


Positive investment Installing the Cablevey equipment also led to


a reduction in energy consumption through the replacement of four drive units with a sin- gle 5hp motor, and the primary justification for choosing the company’s technology – reduced product damage - was met with no measurable damage of any type being caused by the new conveyor. SWDCC spokesperson Charles Carrier


said: "Overall, Cablevey has been a posi- tive investment in improving process capa- bility, product integrity and consistency, resulting in enhanced customer service and satisfaction." The second application of Cablevey tech-


nology was in the cocoa market, rather than coffee and was undertaken on behalf of Cadbury, the multinational chocolate manufac- turer, at its plant in Singapore. The product to be transported is cocoa nibs. The Singapore facility processes a range of


products, including cocoa. Raw cocoa beans are roasted into cocoa nibs, and then processed into cocoa powder, cocoa butter and other products. Like other processors, the company utilised traditional conveyors such as pneumatic conveyors and bucket elevators. However, cocoa beans and cocoa nibs can be


Cablevey is long-established as one of the leading suppliers of conveyors for whole bean and


ground coffee. The flexibility of its technology is demonstrated by equipment for two completely


different types of product - whole bean coffee and cocoa nibs


quite abrasive and cause problems in many conveying systems. A spokesperson for Cablevey said the client had problems with a pneumatic conveyor


conveying cocoa nibs. The conveyor accepted the hot nibs from an auger and fed them to two silos in separate rooms. Sometimes, the con- veyor would become blocked due to variations in the product or aspiration failure, and the driv- ing force of the conveying air was insufficient to break through. The company therefore needed a conveyor that had a mechanical drive, which would not experience blockages, and had the flexible layout to match existing sources and destinations. Cablevey supplied a 4in conveyor capable


of moving 21,000lb/hour (9,500kg/hour) of cocoa nibs to replace their old pneumatic con- veyor. The components removed from the old conveyor included a high energy blower, a rotary valve, two cyclones and two dust take- away systems. The rotary valve could be removed as the feed into the inlet of the Cablevey conveyor was sufficiently regulated by the auger feeding it. After commissioning it was apparent once


again how quiet the Cablevey equipment was. "If the visual inspection tube wasn’t installed, it would be difficult to determine it was actually operating," said the company. "Even with the blower located in a separate blower room, the old pneumatic conveyor significantly added to the overall noise level."


Power savings Adding up the power ratings on all of the


motors on the old pneumatic system and comparing the total with the single 5hp motor on the new Cablevey equipment resulted in an estimated 70 per cent reduction in power consumption. The installation is still only a few weeks old,


but so far it has not experienced any block- ages and the client wants to investigate replac- ing other traditional conveyors but wants to evaluate the Cablevey for a few more months to ensure it is operating smoothly. One possi- bility is to replace all of its pneumatic convey- ors, as this would free-up a noisy under-utilized space in the blower room.  C&CI


May 2011 C&CI


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