Re-use of water: Savings pour in

When an old water purification plant at Parker Domnick Hunter was no longer able to keep up with demand, Elga Process Water came up with a cost effective solution that also allows waste water to be re-used

Parker Domnick Hunter manufactures filtration, separation and purification products for a wide range of industries and applications. It uses a lot of high purity water and water quality is critical to maintaining high manufacturing quality standard.

Derek Calder, manufacturing engineering, explains: "Our filters go into many pharmaceutical and food and beverage systems, so water of pharmaceutical quality is of paramount importance for flushing and testing finished filters. Our production schedule means that we need it 24/7." Increased production had pushed the company's pharmaceutical grade water usage up to around 18,000L/h, and its old water purification plant was no longer able to keep up with the demand. It was time for a replacement; but finding a plant of sufficient capacity that could be installed in the available space in the plant room without major loss of production proved difficult. ELGA Process Water, a division of Veolia Water Solutions & Technologies came up with a solution.

In terms of water quality, ELGA Process Water's ORION packaged pharmaceutical water system would have afforded a solution, had it not been for the fact that the 6000L/h output of the standard ORION was too small to meet demand. ELGA Process Water's engineers set about designing a bespoke system using similar process technology: softeners followed by cartridge filters and then a combination of reverse osmosis, continuous electro-deionisation and ultrafiltration.

That was the easy part, as Dave Clarke, project engineer, explains: "To minimise production downtime we carried out most of the work during phased out-of-hours shutdowns." This included installing all the necessary tanks, vessels and distribution loops which would feed the production areas, while production needs were still met by the old plant. Installation of the new plant also needed some thought. Clarke continues: "We realised early on that the fully assembled plant was too large to go through the plant room doors, so we adopted a design based on easily manoeuvrable, skid-mounted modules that could be assembled inside the plant room. The skids were designed to fit around the constraints of the plant room floor." The specially designed plant was built and assembled at ELGA Process Water's factory in Stoke-on-Trent and wet tested. After factory acceptance testing and full validation the plant was broken down into its component skids and transported to site. Here, it was rebuilt in it's final position in the plant room and re-commissioned. Parker Domnick Hunter's new plant was supplied with full Design Qualification and Installation Qualification documentation including the URS, detailed design calculations, software code review and drawings.Wet test and calibration certificates met most of Operational Qualification procedures and final system validation on site was completed swiftly. Eliminating the need for on-site testing meant that the final changeover from the old plant to the new one was achieved quickly and without disrupting production.

ELGA Process Water was also responsible for decommissioning the old plant, including the safe disposal of chemicals, ion exchange resins and similar waste materials - a task that the company's ion exchange resin regeneration team carry out regularly and for which they have all the necessary licences and procedures.

But even here a bit of thoughtful engineering paid dividends: the reverse osmosis section of the old plant was retained and connected to recover the waste water from production.

It is now re-used as feed to the new plant, reducing mains water consumption by about 50% and saving money.

ELGA Process Water's water has a long history of engineering bespoke designs and a flexible approach to 'specials'. This, together with the best practices learned from half a century of manufacturing standard packaged plants like the ORION, provided Parker Domnick Hunter with a cost effective solution to its water treatment challenge, with minimum loss and with the bonus of wastewater recovery.