Spray nozzle assembly for spray dryer

In a spray dryer apparatus having a housing defining a spray drying chamber wherein a slurry is dried by contact with a hot drying gas, a drying gas supply duct having an outlet in flow communication with said drying chamber through a gas inlet opening in the roof of said housing, and a spray head assembly of the type having an annular swirler vane assembly disposed about the gas inlet in the roof of said spray dryer housing intermediate the outlet of the drying gas supply duct and the top of said spray dryer housing thereby defining an annular flow passageway through which the drying gas passes from the outlet of the drying gas supply duct into the spray drying chamber, an atomizing spray head housing disposed coaxially within the center of said annular swirler vane assembly, said atomizing spray head housing having a floor with a central opening therein and a flange at its upper end, and an atomizing spray head disposed at the central opening in the floor of said atomizing spray head housing and having tip means extending through the central opening for introducing the slurry to be dried into said drying chamber;

• an improved means for releasably supporting the spray head within said housing in sealed relationship therewith comprising:
• a. an elongated guide tube having a conical outwardly-flared flange at its lower end adapted to mate with the flange of said atomizing spray head housing and extending upwardly through the drying gas supply duct to terminate in a capped upper end disposed externally of the drying gas supply duct;
• b. an elongated seal sleeve mounted to and extending downward from said guide tube at the point near where the lower end of said guide tube flares outwardly, said seal sleeve forming an extension of the tubular portion of said guide tube into the interior space of the outwardly-flared flange thereof;
• c. a support tube extending upwardly from said atomizing spray head into said seal sleeve, said support tube being slidably translatable within said seal sleeve and said guide tube so as to permit said support tube and the atomizing spray head attached thereto to be withdrawn upwardly through the guide tube to a location exterior of the drying gas supply duct;
• d. means passing through said guide tube for supplying slurry to said spray head;
• e. first seal means disposed between said support tube and said seal sleeve for providing a gas tight seal between the interior of said guide tube and the interior of said atomizing spray head housing;
• and
• f. second seal means disposed at the lower end of said spray head for providing a gas tight seal between the interior of said atomizing spray head housing and said spray drying chamber.