Investigation into the design and development of a disinfection system utilising a novel spill-return atomiser (SRA)

• Main Author: Stewart, Joseph Alexander
• Published: University of Salford 2011
• Subjects: 615.5
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543503

A novel mobile fine spray unit, utilising a Spill-Return Atomiser® (SRA) has been designed and developed for the purpose of decontamination within healthcare environments. The unit is able to spray uniformly onto any given surface, providing 'mist like' coverage. The high liquid pressure fine spray swirl atomiser that has been developed incorporates a spill-return orifice into the rear face of the swirl chamber with the aim of giving a significant reduction in flow rate whilst maintaining droplet size. Initial work modified a commercial atomiser to add spill-return. However drop sizes were considered to be too large and a new design was constructed based upon earlier work on efficient high pressure (up to 12MPa) swirl atomisation. The atomiser was characterised for different geometries, supply pressures and spill return orifice sizes using a Laser Particle Sizer (Malvern Mastersizer-X) and Phase Doppler Anemometry (PDA). Spill-Return Swirl Atomiser (SRA) with a long swirl chamber was also designed and experimentally tested. This was found to have a direct reflection on the control of spray characteristics and the determination of the coating performance of the SRA on various surfaces in achieving the desired efficiency in the disinfection procedure. The subsequent coating and coverage produced by the SRA was analysed both quantatively and qualitatively via a range of test procedures. The investigation has found that the utilisation of fine sprays (15um<D32<25um) at high liquid pressure (<12MPa) and low flow rates (<0.3 1/min) is indeed suitable for surface disinfection in healthcare applications (i.e. MRSA, VRSA etc.). Moreover, the resulting fine sprays can be used for various applications such as humidification, cleaning, coating, cooling and decontamination. The prototype disinfection system designed together with the market analysis which were subsequently manufactured and tested by the respective international company in Manchester, Hughes Safety Shower Ltd. The system is currently going under clinical trials within NHS and is scheduled to be fully launched during 2013/2014 by the company