Evaluation of compressed air adsorption dryer with three different heat regeneration modes

Abstract

Abstract Compressed air without any traces of moisture is utmost important in several engineering applications. Heat regeneration-based adsorption dryer is mostly preferred to treat compressed air to ultra-low dew point. In this work, the essential characteristics of the different types heat regeneration mode adsorption dryer namely internal heating mode, external heating mode and compressed air heating mode are experimentally studied. The principal calculation schemes of adsorption dryers are based on the previous work and the calculations form the basis of a logical comparison between systems. The system assessment is carried out on common performance range for all modes namely compressed air output of 1000 to 5000 m3/hr, operating pressure of 5 to 10 bar, and feed air temperature of 25 to 45°C. The results revealed that the characteristic specific energy requirement in terms of electrical energy for internal heating regeneration, external heating regeneration and compressor air heating regeneration are 0.176 kW/m3/min,0.342 kW/m3/min, and 0 kW/m3/min respectively. In addition to that the characteristic specific energy requirement in terms of dried regeneration air requirement for internal heating, external heating and compressor air heating are 0.203 kW/m3/min,0 kW/m3/min, and 0 kW/m3/min respectively. It is also concluded that the energy and capital cost referred to 35°C feed air temperature and 8 bar abs. feed air pressure for 3000 m3/hr volume flow rate of product air attracts same amount for all the three modes of heat regeneration. Thus, a system comparison with reproducible dryer data for the varying performance ranges can be developed and utilized for practical purposes.