The investment, which has been used to solve limescale issues affecting the batch sugar dissolution tank feed system at one of the manufacturer’s UK plants, has reduced unscheduled downtime, increased component longevity and saved on production costs. Results have been so impressive that the manufacturer has since installed two further KalGUARD units in order to treat all of the factory’s process water and mains water supplies.  

The food manufacturer’s plant is located in an area served by medium hardness mains water. Limescale is a potential problem in all hard water areas, and even more so where process water temperature is elevated (as calcium salts exhibit inverse solubility as temperatures rise) and there is a phosphate component in the mains water. Such is the case with a particular process at the manufacturing plant, the batch sugar dissolution tank feed system, where large amounts of granulated sugar are dissolved in hot water at 80°C using a stirrer. The water for dissolving the sugar is pre-heated in a separate vessel with a steam jacket lining.  

Prior to adopting KalGUARD, the vessel suffered from hard and tenacious limescale deposits on its inner surfaces, as might be expected of water heated to this high temperature. The deposits were causing a number of costly and disruptive issues. Firstly, they would detach from the walls and pass forward in the system causing blockages. Secondly, the hard deposits were damaging pump impellers resulting in wear and premature failure. Also, scale problems meant the tank had to be taken out of service for deep cleaning, resulting in unscheduled downtime. In order to ameliorate the limescale issues, a dual water feed system had to be installed so the plant could at least complete its required production.  

To permanently prevent limescale affecting the sugar dissolving process, the site’s engineering management team purchased a 28mm KalGUARD system from Sentinel Commercial. KalGUARD is a WRAS-approved electrolytic scale inhibitor device for commercial hot water systems, and represents an extremely low maintenance way (a twice annual service is all that is recommended) to protect facilities against the damaging and expensive impact of limescale. The technology it uses is listed in the Building Services Compliance Guide to Part L of the UK Building Regulations and has been independently proven by Cranfield University as effective in preventing limescale build-up. KalGUARD works by releasing tiny amounts of zinc into the water which turns deposit-forming calcite (limescale) into non deposit-forming aragonite. This process requires no salt and does not waste any water. The unit comes with a controller which can be programmed into a site’s Building Management System (BMS), where fitted, enabling easy monitoring of its operation.

Shortly after KalGUARD’s installation, the manufacturing plant noticed a substantial difference to the tank base, which – for the first time – appeared clean and free of deposits (in fact, power tool scoring marks from a pre-installation clean were still visible). The walls of the vessel were also free of limescale deposits. Based on the visual evidence, the site’s engineering management team confirmed the beneficial effects of KalGUARD, and stated that there is now no further requirement to clean inside the tank. 

The manufacturer has now installed two large 76mm KalGUARD systems to treat all of the factory’s process water and mains water supplies. Furthermore, it has taken up Sentinel Commercial’s field technical service agreement option, which delivers a planned service visit and diagnostic check of the anode condition. The Sentinel technician will also check the water chemistry, filter and controller to ensure optimum limescale prevention performance moving forward.