An innovative unit for water desalination based on humidification dehumidification technique

Abstract

An innovative humidification – dehumidification (H-D) system, consisting of two primary components, a humidifier, and a condenser, was designed and built, together with its various accessories, to generate desalinated water from seawater simply and cost-effectively. The experimental work was split into two parts. The first was concerned with the humidification of ambient air in a specifically designed and developed humidifier. The influence of significant factors on the % relative humidity of the humidified air, as well as the temperatures of the exiting air and water, was examined using the natural draft and air-blown forced convection. The second part pertained to combined H – D of air to produce desalinated water. The findings revealed the presence of a hydrophilic plant (Loofa Egyptiaca) as packing that has never been utilized previously, is branching and mimics structured packing to a large extent. The presence of four stages, each with just a shallow Loofa bed height, was enough to create exit air with 100 % relative humidity. The unit's daily productivity was highest (133.72 kg water per total volume of packed section) at high water flow rates and temperatures (60 °C), as well as when using cold water in the condenser, with a condensation efficiency of 93.5 % without the need for more complicated and expensive coil-type or finned tube-copper condensers. Furthermore, completely desalinated water was produced, which was superior to potable water.

Keywords

• Desalination
• Humidification – Dehumidification
• Loofa Egyptiaca
• Humid air
• Water resources