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Vapour Compression Distillation combining innovative components for highly energy efficient water purification and recovery.

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Project Metadata ElementDetails
  Project Title Vapour Compression Distillation combining innovative components for highly energy efficient water purification and recovery.
Research Area Water
Project Acronym
  Principal Investigator or Lead Irish Partner Sten Bjorsell
  Lead Institution or Organisation Ship Company Ltd.
 Lead Country Ireland
 Latitude, Longitude (of Lead Institution) 51.90648, -8.97791
  Lead Funding Entity Environmental Protection Agency
  Approximate Project Start Date 19/12/2005
  Approximate Project Finishing Date 19/06/2007
  Project Website (if any)
  Links to other Web-based resources
 Project Keywords Manufacture; Energy efficient; Water purification; Water vapour
  Project Abstract Ship Company Ltd (Ship) has specialised in the manufacture of small and medium volume single double-sided and multilayer Printed Circuit Boards (PCBs) for the electronics industry. They also provided hard gold over nickel and wire bonding quality gold on the whole PCB. SHIP wanted to develop a process that was in part based on earlier ideas and in part conceived during their Phase 2 CGPP project. The objective was to develop an energy efficient system for purifying water by capturing the heat energy contained in water vapour. The driving forces of the project were scarcity of water and increased cost of energy. These are common problems for companies in Ireland across Europe and worldwide. Many systems have been developed to purify water. One is Vapour Compression Distillation (VCD) that uses compressors to condense water vapour and heat exchangers to deliver and capture the heat energy. The disadvantages of conventional VCD units are the energy needed for compression and the requirement to have a leak free design. The engineering necessary adds to the initial construction costs plus running costs with replacement of seals etc. The initial design was based on the concept that the air above a dilute salt solution has a higher vapour pressure than the air above a concentrated salt solution. Trials and small laboratory scale rigs were set up in Inter-Euro Technology Ltd (IET) in Carlow to test the concept. Ongoing discussions between IET and Ship led to the design being modified and simplified by passing air through successive sprays of either ordinary water or a concentrated solution of a salt such as magnesium chloride. Although the only energy input was low pressure spray temperature increases of over 4 oC were achieved within a few minutes. Yet to be tested are concepts to expand the 4 oC increase closer to its theoretical maximum and introduce feed back to raise overall temperature differences beyond the single step maximum. The design developed in this project is innovative in that it captures the heat of vapour of water in a design which does not need a leak free system and which only uses low energy pumps to generate a fine mist of either ordinary water or a concentrated solution.