A pressure feed vessel enables 100% discharge of the liquid component through a spray bar and into the blending zone, ensuring even mixing and consistent batches. Using a pressure feed vessel and spray bar facilitates liquid addition while the blender is closed, minimizing dusting and safety issues. The spray bar typically includes four or more spray nozzles so that liquids are uniformly distributed along the entire length of the blender, and the pressure feed vessel eliminates the need for a pump to deliver liquids to the spray bar. It is designed for compressed air supply up to 20 psig or higher.