b'ENERGY EFFICIENCIESthe absolute velocity towards the end ofa homogenous flow and often will notdewatering, as opposed to felt dewatering the blade section in turn, increases thebe able to provide continuous accuraterequiring higher vacuum levels and thus kinetic energy and dynamic pressuredata from such variating circumstances.energy demandinghigher air flows. across the impeller.Runtech EcoFlow meters areFit-for-purposedoctoring and save-all designed to measure water flow acrossequipment allows the felts to run wet, RELIABLE DEWATERINGTHE BASIS FORa mechanical restriction and are notcollecting water in the pans enabling RUNNABILITYsensitive to entrained air or foaming.higher dewatering, higher felt lifetime Each vacuum element in the machine,These devices are used both underand better moisture profiles to improve such as a suction box or a suction roll,vacuum (in a separator drop leg) and inrunnability. Suction rolls are often requires a certain amount of air flowatmospheric conditions.equipped with double doctors to prevent to operate at an ideal vacuum level,re-wetting and maximize void volume i.e. at the minimum to maximize theThe third fundamental issue in anto allow best water removal. Save-all energy efficiency while maintaining theenergy efficient vacuum system is thepans should be designed to manage runnability and dewatering capacity.dewatering and doctoring. These are notthe water that is removed from the nips, The needed capacity is dependentonly related to energy consumption, butand engineered to be rigid enough to upon felt life and type, paper grade,also play a major role in paper machineaccommodate doctor holders. Runtech basis weight, machine speed etc.runnability (profiles), efficiency (dirt andis one of the leading suppliers for the In order to achieve this challengingbreaks) and profitability. Therefore, aimproved dewatering and doctoring goal, we need reliable dewateringwell-designed and operated dewateringsolutions for all kinds of pulp, paper, measurements. The water that isand doctoring system is one of the keboard and tissue machines. In many removed from the paper sheet isingredients of a well-performing andcases, Runtechs solutions have led to a multiphase flow containing solidenergy-efficient machine. a 1-3% increase in dryness after the particles as well as air, thus beingpress section which saves a considerable often subject to foaming. TraditionalThe most economical method ofamount of energy in the dryer section magnetic liquid flow meters demandwater removal in a press section is nip(4-12% less steam). a well-designed and operated dewatering and doctoring system is one of the keyingredients of a well-performing and energy-efficient Figure 3. Comparison of single and two-turbo systems operation and efficiency.machine.30 TISSUE TECHNOLOGY INTERNATIONAL'