variavel0=<b>João Carlos Martins Coelho</b> - jcmc@ipt.br Escola de Engenharia Mauá
<b>Marco Antônio Soares de Paiva</b> - mpaiva@ipt.br Escola de Engenharia Mauá
<b>Roberto de Aguiar Peixoto</b> - robertopeixoto@maua.br Escola de Engenharia Mauá
<b>Abstract.</b> Usually LPG vaporization is obtained by energy supply destined to phase change in appropriated equipment - vaporizers. This energetic supply often electric energy, has high operational costs. Looking for a economical and safe solution, a mathematical model that describes the thermal process that occurs in a vaporizer formed by a longitudinally finned vertical tube bank was developed. In this equipment the phase change occurs due the energy supply by environment to LPG throughout natural convection heat transfer.The boiling heat transfer inside the tube was determined by using the Chen (1966) model and the heat transfer coefficient between the finned external surface and the environment was obtained by the consideration that the temperature profile is not uniform. This model allows demonstrating the operational availability of this kind of evaporator and shows that the design of this equipment must contemplate the variable temperature profile existence.
<b>Keywords.</b> vaporizer, LPG, natural convection, boiling, fins.