ECOPUMP VACUUM SYSTEM CUTS PAPER MACHINE ENERGY COST

Ecopump controllable vacuum systems have shown 30..70% savings in energy consumption in all of the installations completed so far. The company has been working with energy saving technology since 1989. Late 1990's they set out to develop a controllable vacuum system for paper machines to cut down the energy consumption. The concept is now in commercial use and brings good savings for both existing and new mills. Besides energy saving, other savings are available also in piping and building cost, as well as in water consumption.

There are three components in reducing consumption: first, optimising the capacity to level that matches the need. Often, the vacuum capacity is overdimensioned, because the need for capacity is not exactly known when designing the system. Safety marginals are good thing in principle, but result to unnecessary energy consumption is the system has no capability to adapt to real life needs.

Secondly, using economical pumping technology together with dewatering measurements, the cost can be further reduced. It is often thought, that high vacuum brings high dewatering. But this is in most cases not true. By utilising Ecoflow system, that monitors dewatering flows online, the vacuum levels can be set to maximize and stabilize dewatering all time. Often this optimisation leads to lower vacuums. And lower vacuums lead to lower energy consumption, if the system is based on speed controlled turbo blowers.

Third component comes from heat recovery: most of the pumping energy as well as part of the process heat can be recovered. This energy can be used to heat the hood replacement air or process water.

No seal water is needed, either, which can bring good savings, too. At the same time, the system reliability will be improved. The piping connections are designed so that individual pumps can be serviced while others take care of the process. This way, the system maintenance can be handled practically without any maintenance shutdowns.

Ecopump process engineering group has pragmatic experience from hundreds of paper machines. By working together with the machine personnel we make sure there will be long lasting results.

What it comes to real life experiences, the first installation at Stora Enso Kotka mill has been running since 1999. After some initial adjustments the system has run trouble free. The savings counted some 35% from the situation before. It lead to other vacuum system installations in Stora Enso mills in Anjala, Uimaharju and Imatra, some of them having far better results than this first one. 

Ecopump, M-Real and Metsa Tissue have conducted an energy saving program to cut the power consumption of paper machine vacuum systems. The program consists of a process survey, a rebuild – total or partial – or vacuum system, and system optimization. So far it has been realised in Tako, Kyro, Mantta, Kirkniemi and Kangas mills, altogether 8 paper machines. 30..60% energy savings have been realized in all of these machines, by utilizing Ecopump Turbo technology. At the same time, improvements in dewatering and process control have been made. The same kind of program has been conducted at Georgia Pacific tissue mills in Nokia and Cuijk.