Hygiene and softening performance of washing machine integrated with nanofiltration membrane module system

Membrane systems are a growing technology worldwide. In recent years, studies have shown that the use of membrane systems in many areas is widespread. The steadily decreasing membrane costs allow these systems to be used more often. The main reason for this study is that the washing performance provided by the products in the current washing machine market is declared near the market and alternative technologies that make a difference to improve these existing values are not put into practice. The special design NF membrane modules that are produced in our country for water softening are integrated into the washing machine to create the original side of the thesis. Commercial nanofiltration membrane types, which can be used for water softening in the first stage, have been identified. These membrane types are DOW Filmtec NF 270, DOW Filmtec NF 90, GE Osmonics, TriSep-XN45. Since the water softening and flux performance of the NF 270 and NF 90 membranes are at the desired values module studies have started with these two membrane types. Prior to module studies, CFD analysis was performed to select the appropriate spacer to be used in module construction. According to the results from CFD analysis, 0.66 mm was selected as the optimum spacer with a minimum pressure and speed variation Modules were produced with desired dimensions (4.5x30 cm) and desired membrane area (0.5 m2). The tests of the modules were carried out in a cross-flow system and the flux and hardness removal efficiencies were monitored. Because of these studies, the performance of the NF90 module has reached the desired values and the operation has been continued with this module. Then the long-term performance test of the module was started. The performance test was conducted by using the module in a cross-flow system at constant temperature and pressure for 6 hours during the day and measuring the hardness and flux in hours. Assuming that the washing machine is to be used once every 2 days, the tests were carried out for 45 days and it was thought that this 45-day period corresponds to a 3-month period on the user side. No significant fluctuations in the flux and hardness removal efficiencies of the NF 90 module were observed in the test results. In this case, the NF 90 module did not experience clogging problems after 3 months of use and the module was observed to operate in a stable manner. Arçelik selected a suitable machine for module integration and designed it for the module. First, the integration of the NF module system into the machine has been drawn and simulated with the SolidWorks program. Modules were operated manually outside the machine in the first stage and changes in wash performance were observed. Subsequently, the system consisting of pump, activated carbon, NF module and reservoir was placed in the machine and washing tests started under these conditions. According to the results obtained from the wash tests, it has been determined that this system has a performance enhancing effect on the removal of all reference stains. When the total stain removal effect is considered, it is seen that the washing machine selected as the reference has an increase in stain removal performance. Whether the water treated by the NF membrane module has positive or negative results for bacteriological growth on the laundry was investigated. According to the results of the microbiological analyzes, it has been found that the softened water does not contribute to microbiological cleaning. The NF 90 membrane, which was actively used for 45 days, was autopsied and no inorganic accumulation was found to cause clogging. As a result, the washing performance of the washing machine has been increased with the NF module system used according to the data obtained in this study. These modules, which can be integrated into the washing machine, can be used as an effective method for increasing washing performance.