Experimental investigation of spray dehumidification process for hybrid washing/drying machine

Nowadays, air or water cooled condensers are used to reduce moisture of air which is used in drying machine. Because of some disadvantages of these machines such as long drying times, high energy consumption and high water consumption, a new drying system has been desired. In this investigation it is aimed to decrease the energy and water consumption for drying process. An experimental setup was designed to simulate the hot and humid air which leaves a typical drum. In our experimental setup, subcooled water at a temperature below the dew point of air is injected into the hot and humid air. It is expected to increase the contact area between the water spray and drying air and as a result heat transfer enhances. When moist air interacts with the subcooled water, steam in air condenses on water droplets. Due to condensation latent heat releases and temperature of the water droplets increases. In this system heat transfer is increased due to increased heat transfer area by using water spray. The effects of the water mass flow rate, water spray temperature, spray configuration (parallel/counter), nozzle type and air inlet condition on dehumidification performance were investigated. Results of the present study show that increasing humidity content of air leads to higher dehumidification performance. It was also found that increasing water mass flow rate leads to higher reduction in humidity. In addition spray configuration study revealed that counter flow leads to higher decrease in humidity ratio compared to parallel flow.