Chiller Filtration – SIVA Plastics

Introduction

SIVA Group is a major producer of flexible polyethylene packaging and technical films used in a wide range of industries from food grade packaging to laminating and printing. They currently employ more than 350 team members across 3 sites located on the south coast.

At their primary site, closed circuit chiller systems are used to provide cooling capacity required in the extrusion and manufacture of plastic products.

The Challenge

In an industry that has an inevitable impact on our environment, SIVA takes their responsibility to protect it seriously. They contacted Hydro-X to help them find ways to improve cooling efficiency and reduce energy, water, and chemical usage.

SIVA had highlighted issues with their chiller systems where they were experiencing reduced efficiency and system outages which was leading to decreased product quality.

Chemical analysis of the chilled system process water highlighted heavily elevated levels of total and dissolved metals in the system (Iron and Zinc). Previously, there had been no monitoring or maintenance plan and site were unaware that water pH levels had dropped to 5.0. The low pH, in conjunction with no chemical treatment, had caused heavy corrosion and fouling of the system and had resulted in metal sludge depositing in the pipework of the chiller system.

The Solution

Following BG50 Water Treatment guidance, Hydro-X were able to install continuous mechanical filtration of the chiller system via the Hydro-Fil side stream filter. Over a period of 6 months, metal levels were gradually removed from the system until they had reached levels within BG50 specifications.

In addition to the filtration, a two-part chemical treatment program was conducted. Firstly, chemical dosing was carried out to increase pH to safe operating levels, then dosing of Hydrocor 204 inhibitor was carried out to passivate pipework, protecting it from further corrosion.

Hydrocor 204, a molybdate based inhibitor, was also able to mobilise any deposits on the pipework which could then be captured and removed by the Hydro-Fil unit.

Value added

Due to the fouling within the pipework being removed, the cooling efficiency of SIVA’s chiller systems were restored. Not only did this help them move closer to achieving their environmental goals, we were also able to save the company money in the short and long term as not only will these systems increase the lifetime of the plant equipment but also reduces the energy usage of the plant.

Further cost savings were seen on site as the system outages that SIVA experienced ceased. This led to a significant reduction in the downtime of production and meant fewer callouts to conduct maintenance work when the system did go wrong.