Do You Waste Seal Water

Continuous increases in water consumption and unexpected weather changes have forced many countries to restrict water usage and reconsider new ways to control their water consumption. One way is to increase water rates and taxes to encourage individuals and businesses to use less water, while also improving water saving devices, recycling and technologies. Generally, manufacturing industries are a reasonably small contributor to total water consumption, but the increased water rates and usage restrictions naturally have a great effect on manufacturing industries. Pulp and Paper mills need a lot of fresh water to keep process and machinery running 24 hrs 7 days. Therefore, economical, fresh and clean water is today very important for all paper and pulp mills. In the future, these will be even more important as water costs are expected to increase rapidly and more pressure will be applied by the financial and legislative sectors to reduce water consumption. In many pulp and paper mills, fresh water is becoming more expensive due to continuous water consumption increases resulting from increased production and difficulties in purchasing required water quantities. This price pressure includes both industrial and domestic water users. As the effects of global warming are becoming more evident, even greater restrictions will be in place in regions where annual rain water levels have been minimal around the year. Some paper and pulp mills have done more than others towards saving and re-using water at mills. Often, water saving is ignored and thought to be just an extra cost either during mill construction or during normal operation. Seal water uses clean, fresh water to keep the seal wet and therefore, the pumps and machinery running as well. The seal water system is a major water user at paper and pulp mills. Water is required to keep the seal wet and lubricated during the normal operating times. Commonplace is for the seal water to be run down the drain and wasted away afterwards. Each seal water lubrication circuit uses fresh water. Modern and high production pulp and paper machines use modern water control and monitoring devices, which make it possible to optimise seal water usage and then reduce water costs. Unfortunately in many old paper mills, seal water circuits do not have many water controllers and therefore unnecessary quantities of excess water are used to keep seals and machinery running. It is also typical that, in these situations, paper mill operators do not even know where and how much seal water is wasted. Today, there are modern water control devices available at low cost that make it possible to control and monitor each individual seal water circuit. Also, they make it possible to save water, improve reliability and increase uptime machinery. In this presentation, the typical seal water flow control units, manufactured by Flow Controls Oy from Finland, are described and typical potential savings are presented.