Vacuum Optimization: Maximizing Efficiency and Saving Energy
For substantial energy savings, it’s essential to use vacuum only where it’s most critical. By optimizing vacuum usage, strategically measuring water flow, and implementing EP Turbo Blowers, mills can reduce energy consumption by 30-70 percent. Furthermore, exhaust heat recovery, regular maintenance, and tailored dewatering solutions help achieve remarkable energy savings, ultimately benefiting both the environment and operational efficiency.
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, and based on the findings energy savings are calculated based on EP speed control technology. This way Runtech is able to 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 are able to benchmark the effectiveness of existing vacuum systems, dewatering equipment, suction elements, fabrics, and felts. This experience and expertise allows us to help our customer to get the most out of their papermaking process and vacuum systems.
Runtech Systems developed the EcoFlow dewatering measurement system in the 1980s as a tool to better understand forming and press section dewatering. Measuring water flow accurately is essential for optimizing vacuum levels. Many paper mills tend to 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. Accurate online water flow measurement allows for fine-tuning vacuum levels, ensuring they are neither excessive nor wasteful.
CHANGING CONDITIONS CALL FOR A FLEXIBLE VACUUM SYSTEM
After digging deeper into the impact on dewatering, we realized that the vacuum system needs to be flexible, as paper machine conditions change all the time. For example, 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 with used felt, and this means it is not optimal to have the same amount of vacuum (kPa and/or air flow) in different conditions. Our more than 30 years 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. 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 more than 50 percent or more than 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 the RunEco vacuum solution the 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 percent have been achieved when compared with 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.
The RunEco vacuum system main parts are the EP Turbo Blower, EcoDrop Water Separator and EcoFlow Dewatering Measurement. The whole system is developed specifically to take into account 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. RunEco vacuum system, comprising several smaller-size turbo blowers depending on the machine width, offers superior design and operational advantages. In tissue machines, depending on design and width, the most efficient operation requires sometimes 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.
EXHAUST HEAT RECOVERY FOR COST REDUCTION
The EP Turbo Blower generates a substantial amount of exhaust heat, ranging from 100°C to 180°C. Recovering this heat means reduced steam consumption in the paper machine. Given that steam production is a costly process in papermaking, by utilizing recovered heat to warm shower waters or dryer hoods, substantial cost savings can be achieved. This approach is not only economically advantageous, but also aligns with sustainability goals, as it reduces the need for primary energy sources.
RESULTS WITH RUNECO SYSTEM
Case study, confidential client: New Valmet DCT200 tissue machines TM7, TM8, TM14 and TM22, (trim 5.6 meter, speed 1,800-2,000 m/min)
Case stude, confidential client: New Voith tissue machines TM9, TM10, TM11 and TM12 (trim 5.6 meter, speed 2,000 m/min)
Another confidential tissue mill with a machine width of 5.6 m replaced five existing liquid ring pumps by two EP600 Turbo blowers, EcoDrop water separators and Ecoflows. The vacuum system energy consumption dropped from 1250 kW to 400 kW, by 68 percent. The customer installed the RunEco system in two different steps, avoiding long machine shutdowns. After the RunEco installation, the cooling tower for LRPs was dismounted.
An important optimization during the first months of RunEco operation allowed the customer to exceed the expected energy saving, thanks to dewatering analysis with Ecoflows.
The delivery included a speed controlled EP600 Turbo Blower with ABB frequency converter, low vacuum blower for wire section vacuums, EcoDrop water separator, and EcoFlow dewatering measurement for press suction roll save-all and felt Uhle box. PM3 electricity consumption per tonne of paper has dropped by 20 percent. The new system also provides more control – feedback on dewatering flow rates from SPR Saveall Tray and Uhle Box enables vacuum levels to be optimized and prolong felt life.
UNLOCKING YOUR MACHINE’S POTENTIAL
Today, we have sold more than 1,000 Turbo Blowers globally. Given the average energy saving of 45 percent, this translates to energy savings of 2.35 TWh and a reduction of 705,000 tons of CO2 a year. We are committed to helping mills maximize energy savings, improve efficiency, and reduce environmental impact toward a more sustainable and cost-effective paper production industry.
