Find the real reasons for the high energy consumption
Everything starts with an audit. Vacuum levels are studied to identify problem areas and analyze system losses. Based on the findings, energy savings are calculated based on EP speed control technology. This way RUNTECH can give recommendations and proposals for the best course of action as well as ROI calculations. With the experience of thousands of audits and studies at paper mills, we can benchmark the effectiveness of existing vacuum systems, dewatering equipment, suction elements, fabrics and felts.
Many paper mills use excessively high vacuum levels due to missing or inaccurate water removal information.
EcoFlow dewatering meters are designed to address this challenge by measuring water flow across mechanical restrictions, unaffected by entrained air or foaming.
Changing conditions call for a flexible vacuum system
Vacuum system needs to be flexible, as paper machine conditions change all the time, e.g. the machine speed can easily vary from 900 to 2,000 m/min depending on basis weight, furnish and felt condition changes over time. New felt is also different compared to the old felt and this means it is not optimal to have the same amount of vacuum (kPa and/or air flow) in different conditions. Our over 30-year experience in the field has taught us the importance of measuring water removal and controlling vacuum levels. Traditional vacuum technologies proved unsuitable when the target was to optimize vacuum levels, minimize energy consumption and adapt to changing conditions.
Energy saving and vacuum system optimization
New paper machines especially have always presented a major challenge. Machine suppliers tend to play on the safe side and provide highly oversized vacuum specifications. Runtech has rebuilt 3 to 4 year-old vacuum systems, resulting in energy savings of over 50% or over 10 GWh/year. Unless you specify the vacuum system for your machine supplier, that provider will often deliver the lowest cost option in terms of the purchase price without considering the lifecycle costs. In RunEco vacuum solution traditional method of increasing vacuum levels is replaced with speed adjustable turbo blowers, optimal doctoring and save-all systems with online dewatering measurements.
The power of EP Turbo Blowers
Switching to EP Turbo Blowers is a game-changer in energy efficiency. In numerous rebuild projects, energy savings of 40-70% have been achieved when compared to traditional vacuum systems. Energy efficiency, a key feature of the solution, comes from both turbo technology itself, and the ability to measure water removal and adjust the vacuum to the optimal level. RunEco is developed specially to consider the challenges and demands related to the dewatering and runnability of paper machines. EP Turbo Blowers are designed to operate efficiently across a wide range of vacuum levels and air flows allowing paper mills to optimize vacuum levels. High speed motors, driven by frequency converters, allow a typical EP Turbo Blower to provide vacuum levels between 15 and 70 kPa. A wide range of impeller designs allows highly efficient levels across the operating range. We emphasize the importance of carefully analyzing vacuum connections, levels, and system operation. In tissue machines, depending on design and width, the most efficient operation sometimes requires one and sometimes two turbo blowers. Additionally, Runtech is the sole provider of both dry and liquid ring pump technology, to form a combination of both technologies – a hybrid system, allowing us to cater to diverse customer demands, needs and budgets.
The EP Turbo Blower’s water-free design not only reduces water and chemical consumption within the vacuum system but also eliminates the need for water-related equipment like cooling towers and circulating pumps. Furthermore, the RunEco system offers several benefits, including impellers fitted on motor shafts without the need for a gearbox, fast and straightforward maintenance, energy recovery through a heat exchanger on the exhaust line, a compact and lightweight design that is easy to install in rebuild projects and the ability to install it step by step with minimal shutdown time and easy back-up connection ensuring operational safety.
A e B: Two turbo system for double width tissue machines allows different vacuum levels for suction roll and Uhle boxes without negative throttling losses. Suction roll vacuum can be adjusted independently depending on the machine speed. The Uhle box vacuum level depends on the felt condition so it can vary between -15 and -60 kPa. Optimal vacuum level can be found by using EcoFlow dewatering measurement system. Wide operating window of Runtech turbo blowers guarantees optimal power consumption in all felt conditions, even the air flows would be much lower than machine supplier specifications. The two turbo system also has plenty of redundant capacity, which ensures operational safety.
