| CPC B01J 2/04 (2013.01) [B05B 5/081 (2013.01); B05B 5/087 (2013.01)] | 13 Claims |
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1. An electrostatic spray drying system for drying liquid into powder form comprising:
an elongated structural 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;
an electrostatic spray nozzle supported in said upper closure arrangement;
said electrostatic spray nozzle including a nozzle body having a discharge spray tip at a downstream end for directing liquid into said drying chamber;
said electrostatic spray nozzle having a liquid inlet for coupling to a supply of liquid to be discharged into the drying chamber and an electrode for coupling to an electrical source for electrically charging liquid passing through said spray nozzle for discharge from said discharge spray tip into said drying chamber as fine liquid particles;
said upper closure arrangement having a drying gas inlet for directing heated drying gas into said drying chamber for drying the discharged liquid particles into powder;
said lower closure arrangement including a powder direction plenum for receiving drying gas and entrained powder from said drying chamber;
a powder separation plenum downstream of said powder direction plenum; a connecting conduit between said powder direction plenum and said powder separation plenum for directing dried powder and gas exiting the powder direction plenum to said powder separation plenum; said powder separation plenum including at least one filter element for separating dried powder from the drying gas and directing separated gas to a gas outlet of the powder separation plenum while directing separated dried powder to a powder collection container;
said powder direction plenum including an outer water jacket heat exchanger disposed in surrounding relation to said powder direction plenum for cooling the drying gas and entrained powder during passage through said powder direction plenum upon discharge from said drying chamber for reducing exposure of the powder to damaging temperatures; said powder direction plenum water jacket heat exchanger including a cooling water inlet adjacent one end coupled to a cooling water supply and a cooling water outlet adjacent an opposite end of the powder direction plenum water jacket heat exchanger such that the cooling water from said cooling water supply continuously flows through the powder direction plenum water jacket heat exchanger;
a connecting conduit water jacket heat exchanger defining an annular cooling water passage in surrounding relation to said connecting conduit; a cooling water inlet adjacent one end of the connecting conduit water jacket heat exchanger annular cooling water passage and a cooling water outlet adjacent an opposite end of said connecting conduit water jacket heat exchanger annular cooling water passage such that cooling water supplied to said connecting conduit water jacket heat exchanger cooling water inlet is continuously directed through said annular cooling water passage of said connecting conduit water jacket heat exchanger for further cooling drying gas and powder exiting the powder direction plenum prior to entering the powder separation plenum and direction to the powder collection container.
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