Spray dryer with improved exhaust gas filtration system

A spray dryer for drying liquid into powder comprising:

• an elongated body supported in upright position;
• an upper end closure arrangement and a lower end closure arrangement at opposite upper and lower ends of the elongated body, respectively for forming a drying chamber within said elongated body;
• a spray nozzle assembly supported in said upper end closure arrangement;
• said spray nozzle assembly including a nozzle body having a liquid inlet for coupling to a supply of liquid and a discharge spray tip assembly at a downstream end for directing liquid to be dried into said drying chamber;
• said upper end closure arrangement having a drying gas inlet for introducing drying gas into said drying chamber for drying liquid directed into the drying chamber into powder;
• said lower end closure arrangement including a filter element housing communicating with a bottom powder collection chamber disposed below said filter element housing that collects dried powder from said drying chamber;
• a dried powder directing plenum for directing powder from said drying chamber to said powder collection chamber;
• an exhaust gas chamber disposed between said drying chamber and said filter element housing having an exhaust gas outlet;
• a plurality of cylindrical filter elements supported in depending position from a bottom wall of said exhaust chamber;
• said cylindrical filter elements each being closed at a bottom end and having an opposite open upper end communicating with said exhaust chamber such that drying gas exiting the powder collection chamber passes through a cylindrical side of the filter element which restrains gas borne powder with drying gas which then proceeds out the open upper end into and through said exhaust chamber and exhaust gas outlet;
• and
• said filter elements each have a respective reverse gas pulse directing device cyclically operable for directing pulses of pressurized gas into an interior of the cylindrical filter element for removing the buildup of powder on an outside cylindrical surface thereof.