Process and equipment for manufacturing polymer enveloped control-released fertilizer

The invention discloses a technics and device belong to material covering technical field for producing polymer envelop with a high molecule for controlled release of fertilizer adopting spray precipitated phase conversion method. The method firstly makes the material grain in a stable circulating fluidized state and then coats the membrane preparation liquid such as organic polymer to the moving grain surface by double-fluid blow head to prompt the phase splitting of the solvent and solute of the membrane preparation liquid which deposits on the grain surface by the means such as heat air. The solvent is volatilizing from the liquid phase to the air phase. The solute transfers from the highly dispersed liquid phase to a solid phase with a transparent film structure. The device comprises: air electric heater, spouted fluidized bed, condensator, solvent absorbing flume and collector thereof, reaction kettle for heating and blending at a constant temperature, double-fluid blow head and circuit thereof and autom