A quench system and process for cooling high temperature gases is presented. The quench system includes a frustum, or conic, shaped section having an inlet at the smaller end of the quench section and the outlet at the larger end of the quench section. The system includes spray nozzles having openings flush with the wall of the quench section. The process includes spraying a large volume of liquid in small droplets for rapid heat transfer and vaporization of the quench liquid.