Spray-drier for the production of atomized ceramic powder from a water suspension of ceramic material

A production method for producing atomized ceramic powder from a water suspension of ceramic material using a spray-drier comprising:

• a main body, which delimits an atomization chamber and comprises at least one discharge outlet configured to let the atomized ceramic powder out of said atomization chamber;
• a feeding system which, in turn, comprises at least one spraying unit;
• a heating system comprising at least one electric heater;
• and a distribution device;
• wherein the production method comprises:
• a feeding step during which said feeding system feeds a water suspension of ceramic material comprising at least 30% by weight of water and a remaining part of solid ceramic material into said spray-drier and said spraying unit sprays said water suspension of ceramic material and sends it, sprayed, into said atomization chamber;
• a heating step, during which said heating system generates a hot gas flow having a temperature of at least 400° C.;
• and
• a distribution step, at least partially following said heating step, during which a distribution device distributes said hot gas flow inside said atomization chamber so that it hits the sprayed water suspension of ceramic material, thus drying the solid ceramic material contained therein and generating atomized ceramic powder;
• said at least one electric heater comprises:
• an outer casing, which delimits a heating chamber;
• an inlet to feed gas into said heating chamber;
• a plurality of electric heating elements, which extend inside said heating chamber and are configured to transfer heat, through Joule effect, to said gas located inside said heating chamber, so that it generates said hot gas flow;
• and a discharge outlet, which is configured to let said hot gas flow out of said heating chamber and is in fluid communication with said distribution device;
• wherein at least part of said electric heating elements comprises an oblong resistive element and a metal cover that has a three-dimensional net-like structure and is arranged so as to at least partially wrap, on the outside, said oblong resistive element and heat, through Joule effect, said gas located inside said heating chamber;
• and
• wherein said heating step comprises:
• a gas-feeding sub-step, during which a gas is fed inside the heating chamber of the electric heater through said inlet;
• a heating sub-step at least partially simultaneous to the gas-feeding sub-step, during which the plurality of electric heating elements that extend inside said heating chamber transfer heat, through Joule effect, to said gas that is inside said heating chamber and generate said hot gas flow;
• and
• a gas-outlet sub-step, during which said hot gas flow leaves said discharge outlet and is transferred to said distribution device.