b'ENERGY EFFICIENCIESTowards energy-efficient and economical tissue production with RunEco solution By Tero Prssinen, Technical Director and Jussi Lahtinen, Sales Director, Runtech Systems Runtech RunEco solution is a fully adjustable, energy-efficient vacuum system for tissue production. It is a tailor-made solution equipped with an optimal save-all and doctoring system, plus online dewatering measurement. RunEco can provide energy savings of between 30-70%, and is applicable to both greenfield and rebuild projects. Vacuum - the result of air being pulled through a restriction - is an expensive tool; it is one of the top three energy consumers in a paper mill. Historically, it has been excessively used. With todays increasing cost of energy and environmental awareness, paper mills are specifically demanding both reduced energy levels and operational costs to help with their competitiveness. Figure 1. EP Turbo Blower is a key element in the RunEco solution.Runtech RunEco vacuum system is developed especially to takesystem. The primary function of a wire-with each other. Turbo blowers have into account the challenges andand press section, i.e. the removalthe benefit of being an inherently demands related to the dewateringof water, needs to be carried outefficient way of compressing air for the and runnability of paper and boardeffectively and reliably. This requiresRuntechmodest compression ratios (less than machines. Traditional method ofspeed-controllable turbo blowers toRunEco3.5) encountered in a paper machine. increasing vacuum levels is replacedcreate the needed optimal vacuumvacuumA turbo blower is, for a given rotational with speed adjustable turbo blowers,level, robust dewatering equipmentsystemspeed and impeller design, a constant optimal doctoring and save-all systemssuch as save-alls and doctoring, andhas beencompression ratio device as opposed to with online dewatering measurements.the means to measure all this reliably,developeda liquid ring pump which is a constant By using only the needed vacuum inwhilst simultaneously capturing enoughto counterdisplacement machine. The power the critical consumers, mills can fullyfeedback to ensure the energy-efficientthe demandsconsumption of a turbo blower elates to benefit from the more efficient nipcontrol of the system.of both thethe air flow that is being compressed to dewatering strategy and save energy.dewateringsatisfy the pre-determined compression Vacuum is created as a result ofand theratio. A constant speed turbo blower RUNECO SOLUTIONOPERATING PRINCIPLES moving air across a restriction. Fans,runnabilityhas a limited range of efficient There are some principles whichturbo blowers and liquid ring pumpsof paperoperation since the paper machine govern the content and operation ofcan each be used to achieve this goaland boardvacuum adjustment outside of the an efficient and eco-friendly vacuumand are also often used in combinationmachines.designed level requires throttling. 28 TISSUE TECHNOLOGY INTERNATIONAL'