Brewery saves water with dry running conveyor

Craft Brew Alliance (CBA), an independent craft brewing company, sought to reduce the amount of water used during production and prevent damage to the equipment and facility by converting its Redhook Brewery bottling line to a dry running System Plast New Generation (NG) conveyor chain and Nolu-S wear track from Emerson Power Transmission Solutions. By doing so, the operation has eliminated 111,000 gallons of water and 675 gallons of soap for lubricating stainless steel chain.

The switch to a dry bottling conveyor is part of a larger set of 5-year sustainability goals that CBA established in 2009. According to the company’s latest sustainability report, it saved $600,000 in 2013 through water re-use/reclamation, advanced lighting and energy management, use of solar energy, use of lighter-weight glass bottles, recycling and diverting 99.4% of waste from its Portland brewery and recycling 100% of the plastic from Redhook’s Portsmouth plant. CBA today uses just 4.73 gallons of water per gallon of beer, while its Portland brewery uses just 4.07 gallons of water per gallon of beer.

The changeover to a dry running conveyor is part of a bottling line overhaul. The bottling line runs 20 hours per day, 4 days per week, typically at 425 bottles per minute. At its fastest single-lane throughput, it runs about 150 fpm. Bottles enter the line from an uncaser, while the empty cases follow the bottles on a parallel conveyor to the case packer at the end. The bottles are mass conveyed about 200 ft, through several 90° turns, across a static transfer plate and into a combiner where they are single-filed at a higher speed through the filler. They are mass conveyed afterward about 100 ft, nesting four-to-five wide, until a combiner again single-files the bottles for the labeler. The bottles are then mass conveyed 100 ft further to the case packer.

Redhook’s bottling line runs about 20 hours per day, 4 days per week at around 450 bottles/minute, or 150 fpm (45 m per minute) at the conveyor’s fastest points.

Engineers were leaning toward standard LF acetal chain, but then learned about the NG chain and Nolu-S wear strips. These were slicker materials, developed specifically to allow dry running, high-speed operation.

The NG conveyor chain is made of a PBT thermoplastic with a low coefficient of friction. The flat conveyor chain lowers power consumption and noise, and can increase chain life up to 50% in some applications. Nolu-S wear strips and guides enable reduced-lubrication and high-speed operation. They are made of an UHMW-PE compound with a solid lubricant. The combination of NG chain and Nolu-S wear strips has a dry coefficient of friction of just 0.13—a fraction of traditional chains in steel and LF acetal—thereby reducing the conveyor’s energy requirements by up to 30%.

Production imperatives at Redhook prevented a prolonged shutdown, so the change to the new plastic chain was done in phases. Everything was torn out down to the frame and then modified as necessary. Key drive components, such as bearings, sensors, sprockets and gear drives, were all replaced.

CBA uses System Plast magnetic tracking chain into and out of the labeler. The radii allow the chain to be lifted out of the track for easy cleaning and are designed with a one-piece supply and return, so there’s no gap where debris can collect, unlike the stainless steel chain. Light weight and low friction also mean it takes less energy to pull the chain.

The bottling line upgrade included System Plast mounted bearings with backside seals, end caps (yellow) and stainless steel inserts designed to withstand chemicals and cleaning solutions.

As of spring 2014, the Redhook bottling line is 100% dry from the uncaser to the rinser, with some sections of old chain still to be replaced. The sound level, which was 95 dBA on the bottling line, is now approximately 91 dBA. The changeover won’t be complete until the pumps, plumbing and nozzles for the water spray system are removed, along with the drip pans. The cost for the conveyor components—inclusive of everything—is about the same as an overhaul using stainless steel chain.

Emerson
www.emerson.com