GB675883A - Improvements in or relating to apparatus and process for spray drying - Google Patents

Abstract

<PICT:0675883/III/1> <PICT:0675883/III/2> A spray drier comprises a cylindrical drying chamber 2 surmounted by a furnace 3 from which hot gases from burners 27 pass into the chamber 2, heat also being radiated into the chamber by the imperforate metal floor 16 of the furnace. Each gas burner 27 is disposed at an angle beween a radius and tangent to the furnace so that the gases pass out in a whirling manner into the drying chamber through an annular passage 22 surrounding a central well 6. Vanes 26 assist the whirling motion. Hot gases may also be admitted to the periphery of the drying chamber through passages 32 fitted with dampers. Material to be dried is sprayed laterally into the hot gases by a rotary sprayer 30 driven by a motor supported at the lower end of a cylinder 80 spaced from the wall of the well 6 for cooling purposes. The motor and sprayer may be withdrawn upwards through the cylinder 80. Slurry to be dried is fed through flexible pipes connected to three pipes, one shown at 59, <PICT:0675883/III/3> passing through a water cooling jacket 55 for the motor, to a distributor 62 beneath the motor provided with three channels each with a depending lip 72 from which the slurry drips on to the sprayer 30. To prevent dried slurry clogging the sprayer when the supply is cut off water may be fed through a pipe 75 and channel 76 in the distributor to the sprayer. The channel 76 has a dam 77 to prevent clogging of the channel with slurry. The water feed may start automatically when the slurry feed stops. Dried material is collected in the cylinder 9 at the bottom of the chamber 2 and is removed through a pipe 11. The cylinder 9 has an eccentric deflecting cone 10. The chamber 2 may be under suction or pressure. Specification 626,455 is referred to.