Overview Of The Dialysis Water Purification System Water used for medical purposes must be clean, safe and devoid of any chemicals. Treating raw water for medical use requires the extraction of impurities in different stages. In the dialysis process, water purification is a critical factor. Clean water devoid of any chemicals and impurities must be supplied to ensure that the water injected into the body is clean. The plant under study in this case used two main processes for purification of dialysis water; these are distillation and the reverse osmosis process. These are discussed below Distillation process This is the first stage of the treatment process. The main equipments for the distillation process include: Feed pump : this is used to feed the water into the tank and ensure that the correct pressure is maintained throughout the purification system. Boiler : the boiler is used to heat the water. The boiling process kills most bacterial and also eliminates chemicals with boiling points higher than that of water. Heat exchanger : the evaporated water from the boiler is passed through the heat exchanger where it loses heat to the working fluid/feed water in the heat exchanger. The heat exchanger allows condensation to take place. Reverse osmosis (RO) treatment This is the second stage of the treatment process, the main equipment include: Reverse osmosis feed motor : this pump ensures that water is pumped to the right pressure throughout the reverse osmosis plant. Sand filters : sand filters are used to remove all the sediments and particles in the water. A series of slow and fast sand filters are used. Normally, water is passed through a sand bed to remove suspended particles. Carbon filtration : since the reverse osmosis plant cannot remove chlorine and chloramines, carbon filters are used to remove them. RO plant : this is at the heart of the treatment plant. It uses reverse osmosis to remove impurities from water. Ultraviolent (UV) disinfection : the UV disinfectors are used to remove bacteria and other pathogens not filtered by the RO system. Other sterilizations methods are also used to ensure that all bacteria and viruses are removed. S torage tank: clean water is stored and then passed through sterilizers before be used for dialysis. Shell And Tube Case Study Introduction One of the main components of the water purification system was the shell and tube heat exchanger. This heat exchanger was used to transfer the heat from steam to the feed water causing condensation. In the shell and tube heat exchanger, the heat energy in the fluid is exchanged. That is, heat in steam is transferred to the feed water flowing through the heat exchanger. The process of distillation is slow and uses a lot of energy due to the boiling and condensation taking place. It is therefore prudent to improve the efficiency of the shell and tube heat exchanger so as to ensure effective cooling process and utilization of energy. In this case study, an evaluation of the shell and tube heat exchanger was done so as to identify inherent problems and develop solutions to improve efficiency. Description of the shell and tube heat exchanger The shell and tube heat exchanger allows heat transfer between two different fluids. Normally, the feed water or the coolant flows through a series of small tubes running axially along the ex