The invention relates to an evaporative cooling device for a viscous fluid comprising:- a vacuum chamber (29), having an upper part (30)wherein the viscous fluid is injected, a lower part (31) extending downwardly from the upper part (30) wherein the viscous fluid is collected by gravitational force, and an outlet pipe located at bottom of lower part (31), through which the viscous fluid is extracted； and- an extraction device (17), comprising a primary pump, fed with viscous fluid from the lower part (31) through the outlet pipe, and a feeding device, located inside the lower part (31) of vacuum chamber (29), which pushes the viscous fluid from the lower part (31) towards the primary pump, through the outlet pipe.The invention also relates to apparatus and method for the sterilization, degassing or water concentration of a viscous fluid comprising the evaporative cooling device.
